To me the difference is quite clear. There was a time when i solely suffered from anxiety, then it eventually trigged derealization.
I'm living inside a dreamworld right now, everything looks odd and i can't seem to find a connection with an object nor person. Whereas with anxiety i was flooded with emotions and connections. i felt the world, but it was too much and it made me panic all the time. But when the anxiety/panic stopped i felt better, i felt relief. Nowadays, relief is something i haven't felt for almost over a year.. I'm always inside this dream and i can't find peace at any place whatsoever, mentally nor physically. I'm not even anxious anymore.
I also had dreams, ambitions and hopes while living with anxiety. I could also laugh with friends.
So yes, the difference is quite clear to me. And to be fair, if you experienced both you should know the difference too.