I'm begging for help

Hello (first of all needed infos haha : im 18 I've panicattacks and general anxiety and NO heart disease.) So I'm at a point where i completely go insane. I can't sleep and i haven't slept for days and weeks in a normal way and that mostly because I have before sleeping some sort of heart flutter but reallyy uncomfortable and scary. Its so scary I think that im abt to have a heart attack or sth .Everyone says it's spychosomatic and when I try to talk to someone about it they ask if I overthink and about what and that i should stop doing that and ask what my problem is (I just now that mostly stress about the symptoms) but I know it's kinda wrong to focuse on the symptoms so thats why I don't know my problem or how to figure it out. Ofc I've little problems but I can't just get a solution In seconds. I just want to sleeppp. It feels like Ill never get rid of that especially because it comes in phases. I don't know what I am doing wrong. What is wrong with me and why does my body react to it in such a extrem way. Help.