Singing and ears

Does anyone here “sing” a lot. I joined a singing group a few months ago and just recently we did two performances. Each time I ended up nearly going deaf at the end of the performance. I know we were having to sing “out” a lot as the group tends to be smaller at the performance but at the end my ears were full up, crackling, popping, it was horrible. It does go after an hour but it keeps happening. Also, halfway through one performance I went really weird, thought it was going into vertigo or I was going to faint and nearly walked off halfway through (either that or sink to the floor), I just mimed the next two songs and I sort of recovered. It wasnt blood sugar as I made sure I ate something beforehand.

It cant be nerves as I had it happen once in rehearsals, but not generally. I dont want to give this up, I am really enjoying it.
Has anyone had the same thing happen?