Having just spent well over a day convincing myself that one of my answers had to be wrong, I suddenly remembered that not all entries are entered the right way up and easily solved a problem that was threatening to send me nuts. Since then, I've cracked the end game and highlighted five of the six type names in the grid. I have one more to find and I've got a feeling my last unsolved clue might provide the answer. It's 29D - and I can't make head nor tail of it.
I also cannot for the life of me figure out how heavyweight pig (with a letter changed?) ends up as what I am pretty sure has to be the answer.
Oh, and this was always my most hated subject!