I went through a pretty similar thing a little over a year ago and to be honest I still think about it pretty frequently. Though I still think about it I’ve stopped thinking about it in a very negative way. It took a while but just accepting that I messed up helped me a lot, and to further that I made sure that I wouldn’t make the same mistake. Put simply I guess I just changed how I thought about it. But as for what I did to fill the void I listened to a lot of music, like a LOT. It gave me a lot of new perspectives and whatnot that helped me get through that period of excessive negative thoughts. I know you said how without someone else to fill that void, but just having people to talk to helped me a lot. My friends gave me a lot to do and talk about so I wouldn’t always be in a bad place. Sorry if this is also long but your post hit home with me haha.

I went through this but me and the bf are still together I would also try to find validation from others . Because my esteem is so low that any compliment would do. You’re strong, and this isn’t your fault some of us were raised with belittling parents. And other things !