A few things that help me. Not sure if they'll help you too but fingers crossed 🤞
Mindfulness, breathing deeply and slowing everything down in my head. Really helpful when you're getting panicky and the anxiety is coming on.
Talking to DH or DM because saying half the imaginary problems out loud makes you realise how daft they sound. (I could tell you some funny stories of things that I've convinced myself I have!!)
Lying down and focussing on different areas of my body and tensing/relaxing muscles (to relax).
Never EVER Googling symptoms. If it's bad, ring 111 or 999. If it's mild, go see your dr or a pharmacist. Never google! You'll convince yourself you have every disease going.
If something is worrying me, I'll choose a date to get it checked out . Like, if this hasn't gone in three days, I'll phone the Dr. Then, i force myself to not think about it for those three days til the deadline is up. Every time an intrusive thought enters my head, I'll say NO, I'm not going to worry until xxxx.
Ultimately, remembering that worrying does NOTHING (has no benefit) is a big help too. Worrying and being anxious isn't going to make me better, all it does it cloud judgement and make things worse. So when anxiety starts, I'll try and talk to it like a child and say no. Go away. Stop. You're not going to help me. I'm not going to worry about this, it's in my head.
Remembering that anxiety itself causes a lot of the symptoms you're probably worried about. Especially if you're so stressed and tired that you become run down. Once, I convinced myself I was ill with a certain disease and got tested, but as soon as the doctor told me I was ok, magically I started sleeping again and I felt better within days!
Waking is always a big help for me. Exercise really can help.
I find stress will exacerbate my anxiety. When something is stressing my out in one area of my life, I'll always fixate on something to do with my health. Now it's so regular as clockwork, I can almost laugh it off as a joke and roll my eyes at myself.
I can't go to sleep in silence (or I sit there thinking and worrying) so I listen to podcasts while drifting off with the timer on.
I think that's all I can think of right now... I hope there's at least one tip in there from my experience that will help you. Xx