<human>: Summarize the given text in a few sentences.

So I have developed really, really bad anxiety and jealousy problems when I like a guy.

It started out from having my past "relationships" (dates, etc.) ending because the guy meets someone else. This happens 99% of the time when I date someone- they meet someone else and abandon our relationship. Even after him and I have been dating for several months.

The things I do is that I obsessively check social media- and worry/wonder where they are if I don't hear from them, and obsess over the minutiae of the relationship. I don't bring it up to them at all- I just sort of melt down on my own and spiral into freakout mode. I constantly worry that they are meeting new people and will leave me. If they become distant, like doesn't text me for a couple days - I assume they met someone else and distance myself - and they usually have met someone else. I never get dumped because I screw up, it's always that I'm not good enough.

My anxiety and fears cause me to panic and overthink what I text the guys, where we go, what we do. I am so fearful of messing up that I often go into panic mode.

For example, the most recent guy I like, and I, have been in a FWB type relationship that I sort of initiated. I like him a lot obviously but I don't want him to feel trapped into dating me, and I am afraid that even if he does agree to date me, that he will meet someone else and leave, He was acting into me but has become distant in the last couple days, and I worry it's because he is still dating around and I am pretty sure he went on a date Saturday night. This in turn makes me feel like other girls are better options than me.

I know I should just chill out and not care so much, but it's not as simple as just saying it. I am in therapy and I don't have any major traumatic childhood abandonment experiences so I'm not sure why I'm like this, beyond it just happens with whoever I date.
<bot>: I have horrendous anxiety over relationships and being abandoned. Has anyone ever been there and can offer things I can do to change my fears/thinking?