How to heal from betrayal

Dear BROOKE, hello! I appreciate your work, it has helped me immensely these past few years. I recently figured out my boyFriend of 13 years hooked up with a friend of mine three times in February. I made him confess. The relationship had Been a struggle for me for the past five years. My father died five years ago, and since his death my grief, and my boyfriend’s depression, kept clashing. He also had been hiding doing drugs and lots of alcohol. He’s pretty much been like My dead conjoined twin that I have been dragging around with me, trying to make a life for us, and taking all the responsibility on for his problems and mental illness. That’s my codependency . In the start our relationship was wildly romantic, we are musicians, and are pretty well known in our niche.
We played many weddings, and people would always say that our love inspired them to be in love. I thought that his depression was a phase, and that I could help him. But instead I just messed with myself by neglecting to care for myself. I think I’ve been preparing for this break up for a long time, but I never thought he would lie to me . I thought if anything we were best friends. I mean 13 years is a long time… The hardest part for me is being lied to. Even though I do think that people are as honest with you as they are with themselves generally.
I have been doing a lot of thought work about trying to own my 50% of this relationship. I have been saying out loud constantly that I’m not a victim, I knew that our relationship was unhappy and I stayed. But still I have my weak moments, and get really nervous to trust anybody. I fret about the past and wonder if he’d been cheating on me on many different occasions. I think maybe he was with one of my other friends, and these kind of thoughts are horrible, and not helping me to heal or live the life I want to live. I mean I do think that I am in the grieving process right now, it’s only been a few weeks, but if you have any suggestions or insight on how I can steer away from hurting my own feelings about this, I would love it. I can imagine so many things I want to do with my life, I felt so trapped before. Sometimes I would see People doing the things I have dreamt of doing and just cry.
I think our pain bodies and the little kids in us were the perfect match.
In many ways my life will be much better. But I miss him, and I’ll always love him.
And I just don’t understand how he Treated me so badly. I don’t understand how someone I love so much could hurt me so much. I guess that’s love right? I don’t know, I thought love was supposed to feel good.
But then again I didn’t have very good examples of love.
Sometimes I think this was an extraordinary gift, to be able to love someone so dearly, and also be hurt so deeply. I know that this heartbreak will provide so much growth for me, and so much reflection. But it still sucks, and I want to know how I can heal and go live more and love more courageously than ever. I imagine throwing all self pity to the wind, accepting reality with open arms and celebrating a new time in my life. But then I’ll miss him. Or see pictures of us with her. While they were sneaking around , and I feel sick. Brooke! What can I do?