I feel helpless

So for a while, I was dating this girl in a same-sex relationship. We were always happy, holding hands, kissing and hanging out. One night after I came home from classes she texted me saying that we were over and felt that we were drifting apart. I was absolutely devastated, and most of the reasons she told me I felt were not present in the relationship. After crying for about thirty minutes, I dry-heaved for a while before going back to sobbing. For weeks I would send them messages that I didn't think about before sending making the situation worse. The breakup caused a lot of panic attacks, depression, and whenever I'm near them or receive a text from them I get shaky and start sweating. In the last two weeks, depression has hit again and I'm getting feelings from the breakup again. I feel like I still love them, but I'm constantly questioning that I would take them back in a heartbeat, but I know it wouldn't be the same. I wish I had just never dated her, and never put myself through what I have