I was mentally abused by someone who was both my partner and closest friend. Recently, I stopped missing them. But bad treatment from their side atill feels as bad as ever. It does not help that it is only getting worse and worse. Recently they have started to insult me, ridicule me for things as silly as not understanding some message they sent. All that while treating stranger girls that they just met with all the biggest respect, throwing compliments at them. In my case, they won't even compliment anymore, just insult and send bland apathetic responses when I do something well.

I do not understand why it is so hard to get detached, any tips? Also it is a purely online relation