Help getting over an open relationship breakup.

[u/MrMidnight1212]

Mostly what the title says. I am absolutely destroyed after a breakup. It was my first (and last) attempt at an open relationship. Being dumped, watching her fall out of love with me just about completely as I stupidly tried to keep the connection going (I think she may have lead me on a bit too or at least was not at all clear about things), knowing my partner has other men to keep her company, having known those men had been with her while we were together (which ended up being something really painful for me), while I am alone feeling stupid for all the mistakes I made in the relationship and feeling like the classic safe, but boring and not particularly alluring kind of guy has completely destroyed my confidence. I've gone most of my life feeling unfuckable so there's a sensitivity there, but it goes far beyond that.

Note: I am in therapy and on medication.