There’s no one that understands my story

So about a month I had to stop smoking weed because I was doing it everyday all day and it started give me heart palpitations and I would go into a panic and it would be an intense panic attack. Then I was doing good, I was living woth my girlfriend at the time cuz I was homeless for a while and had no else to stay with. I had also known them for years and her and your mom took me in and helped me out a lot. Then after about 2 weeks of not smoking anymore, I found out my girlfriend was cheating on me over texts with some guy and I did some snooping and it broke me, I couldn’t even cry, I was shaking my whole body and my chin, I got chills up and down my body and my heart was pounded out of my chest. That through me into the worst panic attack. I couldn’t breathe, I was crying, my thoughts were going around the room and up and down. I thought she would atleast regret it but she was more mad that I invaded her privacy. I left that household two days later and went back with my mom, who stresses me out even more then when I left 4 months ago. But now I’m trying to learn to forgive myself for the things I did in and out of the relationship and why it led up to that, even though I can’t get closure from her. It’s just hard and disappointing sometimes because I have no one supporting or really knowing enough of my story to see how big of a character I have and what I’ve been through in the last three years. Thank you:)