I don't know what it is but messaging certain people can take me from 30 minutes till hours, days maybe even weeks. This surprisingly doesn't go for everyone I know online. I want to message a certain friend but it has been almost 3 days and I'm still unable to. I'm scared of making them tired of me, scared of overwhelming them, burdening them by accidentally messaging them too much. I am also very afraid of them ignoring me. I've known them only since november and they're pretty nice to talk to but I feel like I'm going to ruin all of that. Whenever I don't get a response after a while of waiting I delete the message because I feel like I said something bad or I might've been annoying. I understand that they're human as well and have their own problems but I still feel like everything's my fault and I hate feeling like this daily. 

 I already begin panicking whenever I want to message them but am not able to.

This doesn't go for just to them, I have this with many other people as well and I really want to fix this. It's getting annoying to me and my other friends and it feels like they're eventually going to abandon me for being like this. Being told "don't worry" or "don't overthink" doesn't help since if that were the case, this strange feeling of nervousness would already be "cured". I don't know how to not worry and how not to overthink. I feel like I need a step-by-step tutorial for this at this point. Thanks for reading, please reply if you can help in any way.