6 months of feeling terrible

6 months ago I had a panic attack that threw me into an anxiety spiral that put me in a bad state of derealization and vertigo. Fast forward to today I am feeling much better but still have many of the same issues mainly centred around the back of my neck and head.

- very heavy head

- derealization

- feeling out of it most days

- tight neck and back muscles

- I get dizzy very easily and never use to (especially if my head is moving to fast)

- Every time I get up from a laying down position my head (for maybe 5-10 seconds) feels very weird almost dizzy and off balance

- tension headaches

I understand a lot of these problems stem from major anxiety issues and such but now that I'm feeling better from when it all started I'm starting to get concerned about it not getting much better. I do have very poor posture and read about people having pinched nerves or possibly even arteries that can cause a lot of these problems. Any input would be great thanks.