Please help me, drowning from childhood guilt :(

Please can anyone offer me some advice. A long time ago, 20 odd years even when I was a stupid teenager I did something which has been haunting me for almost 3 years now since I recovered the memory. Here is my story ... when I was a teenager I kind of hung around with some bad people. My brother had a friend his age who seemed to me to be from a very dysfunctional family. His mum used to buy my friends and I cigarettes as we were not old enough. There was a little brother and the woman would always ask me to take him out to 'get him out of her hair'. I would take him to the supermarket and get her shopping for her, take him to park or other times just take him to my parents house and let him play in the garden a while. It is apparent to me now that the mother used me to look after him. When I took him home she was usually off her face from drinking or taking drugs. There were always different people in her house who were high. Sometimes she would be cross that I hadn't been out long enough and she had not had enough time to herself. Other times she would be passed out on the sofa and I felt bad for the children in the house. I never took any drugs and still have not even until this day. I can't remember how it came about but one time she asked me to look after him while she went to buy drugs. I feel disgusted with myself to say that while she was out I touched him innapropriately. I feel unable to go into details as I am too ashamed. I will say however, I did not force him to do anything and I caused him no physical pain. I don't think he was even aware what had happened and the whole incident lasted only minutes. I don't know what came over me but I do know I had not planned this and was a spur of the minute action. Once never repeated. So here I am today riddled with guilt, upset, OCD and anxiety all caused by this one teenage mistake. Again I feel awful to say that I was 14 and him around 2 which makes it even more awful. A short time later my parents got to hear of the drug use at the property and my mother talked of other things she had heard going on there but I never did find out what. My parents forbid me from going there again and I didn't.
So today, I'm in my 30s. Married to my best friend with two amazing children. We own a lovely home and both work alongside volunteering for charities. My act was never repeated and I have no feelings for children. I honestly view this a a crazy one off mistake I made as a stupid stupid teenage kid. I try and think how I would react if my own teenager now had done this. Sure I would be cross, angry ECT but I'm not sure it would warrant the feelings I have for myself. Despite feeling so awful I am slowly working to forgive myself. My husband knows everything and doesn't understand why I feel like I do. He says I was just a kid and kids do awful stupid things sometimes and I should just let it go. He says my suffering is punishment enough. I feel like my children deserve a better mother and would be better off without me, that I don't deserve to be happy.
I worry constantly that the police are coming for me. That the little boy remembers and goes to the police and I'll loose my family. I have panic attacks every day for fear of this happening and cannot enjoy anything anymore as I feel constantly scared. Can anyone tell me what the police would do? My husband says nothing as I was a minor and the boy in question does not remember.
I used to think I was a nice person until I recovered this memory and now I feel like a monster who doesn't deserve to live anymore. Please someone, anyone send me some advice.

Thankyou for your reply snaga. I am working at forgiving myself.
My main concern right now is finding it extremely difficult to move forward as living in fear of the police turning up, taking my children from me ECT. My heart races all day from the fear.
Can you offer any insight on this? I'm in the UK if that helps any.

I guess it's the OCD that gets me stuck on this aspect. My honest thoughts are that I was only a child, one who should never have put in this situation. I feel the mother should have taken charge of her children instead of using a teenage while she was using drugs - I'm not excusing my actions in any way.
I have mostly forgiven myself and know I made a stupid mistake as a teen. I just cant shake the that the police are coming for me. My husband just keeps reminding me that I was a minor and I need to just keep telling myself this is OCD talking. For 21 years I have been a decent person and need to let it go. This happened over half my life ago. I know this but my daily panic attacks still occur that today will be my last with my children. I can't seem to let this aspect go

I find myself in a similar situation. I was 12/13. For me the worst part is this idea that I should not ever be allowed to forgive myself. Ever since I remembered an incident (the memory came to me last year), from that point onwards my outlook on life as a whole just seems numb. Whenever I start to enjoy something that memory comes flying to the front of my brain like a devil saying 'HEY YOU, YOU MONSTER YOU DON'T GET TO ENJOY THIS'. Even though nobody was ever hurt and I am certain they don't recall anything. Not to mention it was also 20 years ago for me, and nothing close was ever repeated.

My point is consider yourself lucky you have forgiven yourself. That's something many can't do, even though they should.I have never been concerned about police and you shouldn't be either. I can 100% guarentee that what you fear won't happen. Children that have made mistakes like that in the past and people have found out close to when it happened, worst case scneario went to some therapy, but not because they are crazy or evil, but it was to be sure it didn't become something that continued in to their future life. Which you have said has not happened and you are 2 decades later, so you need not worry.

I'm curious was to the mindset you took to forgive yourself? as I often sturggle with this.

Thankyou rms18. My husband keeps telling me it's my OCD that makes me worry about that aspect of it. How are you sure the other party in your situation doesn't remember if you don't mind me asking.
It has taken a long time to forgive myself. I recovered this memory in 2016 and only this year I feel that I have. It was hard, however, I realise I was only a child myself. Admittedly an older one but a child none the less. I also tried to think of myself as that child and not the adult I am today. Having children myself I know of children similar ages and I imagine what I would say to them in the same situation. Sure, I would be cross, angry and upset but I would forgiving of them for the very fact they are children. I remember being that age and thinking I knew everything when really looking back I was a stupid kid who did something stupid. Also, I look at the 20 years since the event and can put my hand on my heart and say i am a decent person. I have never done anything like that since. My whole life is centred on doing the best for my children. Being the best mum, wife and friend I can be.
Can I please ask why you say you have not been bothered by the police as I just can't shake the feeling.

And I think you need to be kind to yourself, you were just a child too. Forgive that child and be the best adult you can be. We are no longer these stupid kids. You do deserve happiness and are not a monster - I battled that too! If you were a monster you wouldn't care x

Thankyou, today was a better day for me but today I'm anxious about the police again. How can I be sure they wouldn't be interested. I'm sorry to be a pain and go on