Iam 37 weeks pregnant and am having serious problems with my teeth, please help me dentists...?

I have a tooth that is eating away on my upper right jaw and the hole is so big that a lemon seed could fit in. Iam in so much pain that i can't even chew properly or rinse my mouth thoroughly after brushing my teeth. Taking fluids whether hot,cold or luke warm is terrifying enough to give me a headache. I wake up in the night due to the excruciating pain. I went to see a dentist but i was told at the moment, nothing can be done for me until the birth of the baby but i want other opinions, i just can't imagin myself enduring this pain for the next 3weeks!it's too too much, it's enough that i have to go through labour pains but with a toothache,no way.What pain killer can you recommend?