What to do ...

Okay hopefully I can make this short. I think I'm just being paronoid and FTM. So last few days I've had diarrhea. Multiple times a day. A lot too. Sorry I know tmi. I barley slept last night bc I had tons of cramping and low back pain. I am currently 36 weeks pregnant. Wake up today and I have a doctor's appt later this afternoon. I feel like my child is trying to break free at any angle. I can't close my legs because it literally feels like my inner muscles in my thigh are working to hard. I'm starting to feel lighting crotch. I looked up symptoms and it says it's prelabor symptoms. Am I crazy. Should I go in early? Should I wait? Last time she was measured she was a week and half ahead. I've tried every position to get comfortable. Any advice?