My depression, missing libido and his "virtual infidelity"

For the past 2 weeks it's clear that I need professional help/treatment for my (bipolar1) depression. The hopelessness is so bad that despite my lack of appetite for meds, the question has come down to inpatient or out.
Last night we sat down to discuss options and during a break in the conversation, he left the house and I had an overwhelming urge to check his texts as he has been grouchy often. I am amazed at how calm I was when I found sexts and pix between he and some other woman. On his return to the house I approached him (holding in tears as far as I could) and said "we need to talk and you need to be very honest". I wasn't angry. I was hurt and disappointed but I said that I understood why. I do understand the seduction of the escape and I have put on 20+ lbs since quitting smoking. He has been mostly kind and accommodating otherwise.
One of my problems is that he doesn't see this as cheating. He apologized for hurting me.
I'm reaching out to have a case worker assigned to me as I am totally dependent on him. Other than that I use these online support forums to feel some kind of connection to the world.
Does anyone have any advice for either of us? I'm sure that many of you have lost your sex drives due to the disorder before. I need to be able to trust him.
Thanks for reading.

How difficult it must be for you to deal with infidelity when your BP symptoms are flaring up and you need help! I can't imagine how terrible you must feel right now. IMO, he is cheating on you, however he wants to couch it to make himself feel better. You deserve honesty and fidelity in this relationship. Your putting on weight and lack of sex drive are not excuses to accept his behavior, nor is what he doing your fault. He should have talked with you and together you two could have figured out how to improve your relationship, rather than him just checking out and starting a new one.

That said, I think it's great you're looking ahead to take care of yourself. Getting a case worker is such a good idea, and right now, maybe you just need to focus on getting yourself better and deal with the relationship issues after you're stable enough to manage it. Right now, you are priority #1. When you are better, you could try some couples therapy to address your issues if you want to continue the relationship.

Take care!

Caribee4me said it very well!
Not much I can add.
20 lbs is nothing. I've gained 50!
Those text messages are not innocent.
As the saying goes, "Where there is smoke, there is fire",

Is couples counselling an option for you?

Take care,

Thank you both for your input. We definitely would benefit from counselling but can't afford it. I would like to think that we could talk through a lot of this independently. I haven't really ever had a hard time approaching the hard subjects with him. I was hoping some readers could chime in with what they think needs to be covered. It's been a shocking day and I know MY perspective is off. I want to cover the bases.

Thanks all again

LostIngrid...what do you mean by having your bases covered? Do you mean what steps/action you could take now?

Hi Caribee, I was very emotional when I wrote that and I'm guessing by "covered bases" I was looking for all help to look at my/our situation from "all angles" but mostly was asking you all go help me look out for myself.
Thanks for your inputs.
Ingrid