How to repair broken friendships?

Hello;

I am a older teen who has damaged his friendships due to his toxicity, I have a terrible self esteem, and temper due to my nagging parents, and school bullying/rumours. It has taken a toll on my mental health, leading me to become someone I never wanted to be, a rude, horrible, and constantly venting toxic person. I want that to change, I want to earn my friends’s trust back, I will do anything to cure this sickness. I want help...

Horrible

Lots of people are toxic as teens. Not anything that special. Terrible self esteem also seems to go with it. If you want to change then change. You may need some assistance to be effective so see if you can talk to your parents and let them know you want to be able to see someone. A local doctor can usually help as well if you share your desire to get some professional psychological help.

That said you sound a bit like you are sabotaging yourself and that is ultimately what you may want to work on as once that is done then the rest may be able to fall in place. Specifically you are interpreting your history pretty negatively, assessing yourself negatively and then your primary objective is based on what someone else does (i.e. Friend gives you back their trust)

I'm not a professional so probably take what I say with a grain of salt but you probably need to start by learning how to be kind to yourself and being as mindful of possible about your feelings and your actions. And with that awareness you can assess how you have done and determine what type of changes you want to make as a person.

When you reach the point that you are nice to yourself and that you can act the way you want to act and are happy with then you have succeeded. That friend may come back or they may not, but you would be best served to be kind to yourself and work on yourself in whatever ways you would like to.

And being a teen there will be lots and lots and lots of people in your life and your future. If you are able to be the person you want to be you will have as many trusting friendships as you will probably want to have.