Talk to Gynecologist on Pregnancy-weakness

I’m 6 weeks pregnant and I’m unable to eat anything because of nausea and bitter taste in my mouth, my appetite has reduced so much since the last 2 weeks that now my bp remains very low specially in the morning I’m very dizzy while making breakfast. I used to have a good diet but now all those things i used to eat before makes me nauseous. I do try to take food and fruits in small portions after every few hours but still the weakness remains that i just sleep half of the day because of it even the heart beat is so abnormal that i feel like I’m going to pass out. I have pcos and this is my first pregnancy so I’m even more careful in terms of eating but all i crave is spicy junk foods which I’m avoiding which makes it even harder. My dr has only told me not to take caffeine and chocolates nothing else. Pls help and advise as I can’t deal with this weakness and low levels of bp.