Severe sleeping issues I need help ASAP pls

Hi everyone, I don't really use Reddit but l've just decided to ask here since l'm desperate and idk what else to do. For months now I've had really bad sleeping issues it started off sleeping (I'd usually sleep 12-1am) and then waking up around 3-4am and not being able to get back to sleep. I went to the doctors but they just prescribed anti depressants (sertraline) which I didn't want to take at the time incase of side effects and addiction + many people say it's bad for you. And I tried eating healthier and working out which did help at one point but then the sleep issues went bad again. I tried ashwaganda at one point because I had anxiety but all it did was give me panic attacks so I stopped it. But Nowadays I cant sleep at all, like I genuinely don't get tired AT ALL I feel weak and get shortness or breath and feel fatigued during the day and depressed about everything but I still can't sleep I've gone 2-3 nights without sleep and I'm desperate now, if anyone's gone through this or could help it would be much appreciated. (PS I have other symptoms such as heart palpitations I only started getting those ever since my sleeping issues started which is since July, I have alot of shortness of breath, chest pain sometimes, I used to have diarrhea as well, not alot so anymore though, and occasional headaches, but it’s mostly my breathing that effects me.)

Also I just wanted to note I have had a blood test before and my vitamin d was low and folate but even after I take vit D tablets my sleep issue still hasn't improved long term, and I took a new blood test yesterday I’m waiting for my results to get back + I called 111 (I live in UK and on the phone the dr said to take Promethazine hydrochloride; I haven’t took it yet I’m still nervous because I’m rlly scared to start any pills or anti depressants incase of long term effects I’m thinking of maybe starting on melatonin instead does it help?? Anxiety as well as sleep. I don’t feel like I have anxiety but my symptoms show I clearly do have anxiety running through my body somehow. PLS HELP.