Obviously I wasn't there, but to me it sounds better than how you are interpreting it. You are still cognitively at or above average according to the testing (which is good) but he has recognised that your injury has caused problems which aren't necessarily tested for in these tests (also good - that he has recognised this I mean).

Among these problems is depression, which can be a direct symptom of PCS or can be caused by the stress brought on by the other symptoms of PCS. He thinks you will be able to work again, but advises starting small so as not to overdo things and relapse or make dangerous mistakes. To me this sounds like good advice.

Perhaps you should not go straight back in to a nursing job to start with - maybe look for something with less responsibility and associated stressors and challenges. Hopefully you will improve or learn to work around your remaining deficits to the extent that you can return to nursing, which is obviously something very improtant to you.

Like I said, this all sounds like sound advice to me. Good luck!