Feeling faint and weak

Hello, so far I've been diagnosed with panic disorder and depersonalization/derealization.
I keep going really faint and weak and I have to lie down. I feel so distant and like the floor is coming up to me. This can last all day. I can't stand to be around people when I'm like this I need to lie down and I just feel like crying.
My question is, is this just anxiety and dp or something else?
Thankyou in advance