Feel so insecure

So I just want to vent a bit and if anyone can take the time to read this and give me some advice or anything that would be appreciated!

So I have just been feeling very low and insecure about who I am recently, and it all stems from a recent break up and my friends falling out with me. I am 18 and I see myself as a nice person, and when I was surrounded by friends and my first love who was really loving and sweet I felt confident and secure in myself. I didn’t do anything wrong to end the relationship- he made it very clear that it was due to him not feeling like he could put the time in with his busy work and about to go travelling, but the insecure part of me keeps wondering if he was just saying that and there’s something wrong with me... what if I’m boring? What if I’m annoying? I gave him a lot of space to do what he wanted and never acted clingy but I still worry if I actually did act weird and didn’t realise it? I feel worthless and not good enough, the breakup came very out of the blue as a week or 2 before he ended it we were happier than we’d ever been, I’m constantly doubting myself and if it was real and I can’t get rid of this self doubt.

I went through messages to my old friend this morning and got super upset, I went right back to 2015 and read through stupid things I had forgot I even said and thought... like worrying about other boys I had crushes on even when I was talking to a boy at the time. I was 15-16 and I guess sensibly I can say of course I’ve grown up and I’m not that person and more but the paranoia in me makes me feel like I’m a bad person and that’s why he left me? I probably sound stupid but I can’t get rid of this feeling, I just don’t understand how he could have left me if he ever loved me and it kills me to think he might not even care for me as a friend anymore... ive always suffered from paranoia and needing to be liked so being rejected and left makes me feel like t’s all my fault, I can’t imagine him being sad without me as I don’t value myself at all... is this normal? I just want to be happy again