trouble understanding emotions / relationship problems

i know i’ve been struggling with my moods and thoughts for awhile but it’s never been so apparent till i got in my first relationship. i constantly start problems because i think he’s lying to me and i’ll spiral into negative thoughts when 2 minutes ago i had never thought that in my life. i’m really struggling with believing he’s not cheating on me rn or did something bad. and it’s even worse when i don’t see him because i can’t see what he’s doing on his phone and i just feel more loved when i’m with him rather than just texting him all day. i broke up with him multiple times last month because i just felt so sad all the time when he wouldn’t respond to me fast or call me as much as he used to but it never really stuck. this problem just got brought back up again yesterday because everything that bothers me he doesn’t really see a problem with it or just says he already explained it to me and thinks it’s annoying when i bring it up. i can’t tell if i’m overthinking and making it worse in my head or it’s actually as bad as it seems. i can’t talk to my friends about it cuz i just feel annoying in general talking to my friends about my problems but also because i told them a few things he did awhile ago and they just don’t like him now. i also told them i broke up with him and now they know we’re back together so i don’t wanna seem weak you know .