My nutrionist did check my B-12 Levels. My folate was very low below normal, and my B was at the lowest part of the normal range. He suggested it was probably from the PPI's etc.
I'm sorry you're not feeling better yet, but I'm glad others were able to give you advice.
Main reason I'm commenting is because my tongue has been like that for over 5 years now - I've had tests for thrush, swap tests, etc. and it always comes back normal. My tongue is always swollen, looks EXACTLY like yours and is very sore at times. My doctor claims it's because of my vitamin B12 deficiency, have you had your levels checked?
Hope things get better for you, though!