I have bad depersonalization with anxiety. sometimes i get these split seconds where i feel like i'm going to fade out completely/faint. i don't get hot, tunnel vision or dizzy. it only lasts a few seconds. could that just be the anxiety?

Possibly: It could also be a lot of other things. You should see your GP and discuss this with them. They may want to do some basic tests like check your glucose and do an ECG to check your heart.

Anxiety: The symptoms and signs you describe can very well be anxiety. It would be nice to have your doctor check this out. Then you know it is nothing that is being overlooked. Good luck. Get this checked out.