What Causes Persistent Dizziness, Weakness In Legs And Panic Attacks?

I ve been having dizzy spells for months now and they have done blood tests and ekgs and can t seem to find out what wrong. It s been getting worse and now I feel like I m going to pass out and I feel dizzy from the time I wake up to the time I go to sleep. My hands have been shaking a lot and I feel weak like my legs are going to give out and some times my heart races. They said it could be panic attacks but I don t just get dizzy and feel like im going to faint sometimes it s 24/7. I don t know what it could possibly be but it s scarring me to even get out and drive because I don t want to pass out.