Im 34 weeks pregnant and im very uncomfortable, Is this normal?

I've been having really uncomfortable feelings along with diarrhea, cramping and every time i eat i feel really full even if I didn't eat a lot at all.. I feel like im running out of air and my arms and legs fall asleep too. Im not even that big either, everyone tells me that im so small to be 8 months.. But yeah I sometimes feel nauseous and light headed and im very lazy these days and all i want to do is lay around and do nothing. is this normal?? and also im wondering if anyone else who is 34 weeks or around is experiencing diarrhea and really bad cramping all the sudden from it and then when i go to the washroom i dont feel like i have to go anymore or sometimes i do but not alot.. Im also on iron pills so i dont know if that has anything to do with it cause i have low iron.. But yeah can someone please tell me if these are all normal and if u think i should call someone or what your syptoms are and what i can expect cause this is my first pregnancy and im only 17 soo i dont really know. Thanks