Missing my ex…

I miss my ex terribly. We dated very briefly and during the time we had a few issues that ultimately ended up with us breaking up in bad terms. (Lack of boundaries, cheating ex). I know it’s crazy to want him back but I do. I find myself reading old conversations wishing for that feeling he used to give me. I feel like he was my soulmate. Idk what to do. Should I reach out? I need answers. P