When my anxiety was at its worst I got this a lot. I still feel like I need to lean against something to support myself now and then when I get anxious because I feel like I'm going to faint. For me the derealisation has gone now but yes, I've felt exactly how you feel and it is a reported symptom of anxiety. Since you had an eye twitch and it went away with sleep, perhaps being tired due to your anxiety is causing this? Maybe try to have a nap and see how you feel.
If you really are concerned go to your doctor, though. Even if there's nothing actually wrong with you neurologically they could perhaps refer you to a therapist to help overcome your anxiety.