depersonalization/headache/dizzy/worried

HI there. I've never posted a thread or signed up to anything like this before but im now desperate. (and thank you for taking the time to read)
About 3 months ago i started getting some headaches and they wouldn't go away. So i eventually went to the doctors and after many appointments and A&E visits, i got a ct scan of my sinuses and an mri of my head which came up all clear (great). I then got amitriptyline to treat migranes. Then i wen't to a festival and had one toke of a joint with my friends and mdma which i didn't like AND WILL NEVER have again for the rest of my life. After the festival i starting having depersonalization symptoms which were horrible but im blaming myself for having weed which i think is the cause (although my friends didn't get this). Now, for the last 3 weeks i seem to have strange non-painful but uncomfortable headaches and my stool seems slightly different and i can't eat as much and feel sick much more. I'm a very social, sporty person in fit shape and never had anxiety before in my life. So i am confused as to what this is but i am now living with my ex gf in a house at uni who i still care about a lot and that makes me upset. So i am telling myself that you are losing weight, feeling sick and having different stool because of anxiety all added up, combined with still caring for my ex. These headaches and everything else are taking over my life and i can't take much more. Can anyone relate, or help?
Thank you so much for listening

Hey Henry,

I can relate to headaches, but I also get bad pressure in my head. Like my head feels like it could explode. Many times I question if something is medically wrong with me but doctors told me I'm ok. I also notice when I'm around people who make me happy, the pressure decreases or fully goes away. I am also into sports and I am a runner so I can relate to you in the sense that it all came as a surprise. I think my symptoms of anxiety started about a year ago and I am now just starting to get things under control. The best advice I can give you is to trust the doctors when they say nothing is wrong. Even as I am writing this to you, it is hard for me, but I know deep down its right. If you have been checked and they say your healthy, accept anxiety as soon as you can and than you will be able to start helping yourself. Anyway, I know the physical symptoms are the worst for me, so your not alone.

Feel better,
Kelsey