I don't want attention, I want some advice. I've been feeling pretty depressed over my ex for I don't know how long. What can I do to deal with the depression and sadness.

Edit: With a few comments about not providing enough info about the subject, I'll provide some.

My ex cheated on me and I stayed with her for some reason, she had 3.5 partners at once, she also has more than 6 guys chasing her at one point. She and I broke up and got back together at least eight times over a span of a year. I wasn't her first partner she got with me while being with her first and constantly compared me to him, said how I did some things better and constantly blamed me. Yeah I know the ultimate simp/beta/cuck. I was pretty invested and I put too much time into talking to her because I generally believed she loved me. We were on and off for being friends as well so she was always around. After we broke up this year she told her friends lies about me and I tried to fix it and crap.

My ex was my second and last relationship. I had mgtow knowledge while being with her but the pill took awhile to kick in. I didn't see any red flags until I delve really deep into mgtow. I made a lot of mistakes but I've learnt from them. I am aware I put myself into this situation and I'm aware that I made mistakes

Sorry if it doesn't make sense, something that I'm working on is organizing my thoughts and putting them out.

Thanks brothers