itv Player and Vevo don't work either!

AAAARGGHHHH!!!

^^ What sort of error message (if any) are you getting for ITV Player? (I presume you're in the UK)

It asks me to enter my postcode but then doesn't let me get past that screen when I do.

^^have you tried deleting it and reinstalling? Worst case would be a factory reset.

If there are four things not working then a factory reset sounds like a good idea!

Sometimes just pulling the power out of the back and reconnecting it helps too (I would try that first).

Don't knock the rubber mallet either (excuse the pun). If all else fails, bringing out the rubber mallet usually solves things too.