I been in bed rest for a few months and just stood up and walked. felt ok except for feeling anxiety and dizzy. i heard seizures can happen. true?

Depends: The reason for the bed rest would be the issue w/ respect to seizures. I've never heard of a seizure caused merely by bed rest for months. I'm glad you generally felt okay upon walking a bit. I hope it goes well. Work w/ a physical therapist for best outcome. Knowing your condition, they could advise about risks incl seizure possibilities. Relax and congratulations!