How can I stop feeling bad after sexual acts?

This might be a strange post because there’s no physical sex involved, but I figured this was the best place to post.

I have a long-distance FWB and we sext fairly frequently. I absolutely love it, but after we finish I crash and feel bad in a number of ways. Anxious, nervous, jumpy, easily set off, sad, depressed, etc. and I don’t know why. I’ve looked at postcoital dysphoria and it sort of sounds similar, but I’m not sure if I’d call it that. I am currently on antidepressants and antianxiety meds as well (Wellbutrin and buspirone), although I’m not sure if those have any effect regarding this.

How can I stop this from happening again? They do give me aftercare in that they stay to talk after (either about the session itself or things we normally talk about as friends), and they do comfort me when I voice needing it, but I don’t *want* to need validation every time to feel fine after sexting. I just want to not feel bad to begin with.

I’ve been thinking of asking for more/longer aftercare – which I’m certain they would try if I asked – but I don’t even know what I want or what would help. Has anyone gone through something similar, and if so, what helped you?