Toddler sleep help please😭😭

My toddler is 20 months and used to sleep fine. We would lie him in his cot and put his night light and music on and he would be asleep with in 20 mins and sleep till morning. The last week he is refusing to go to sleep in his cot and I've given in and cuddled him to sleep which I can't continue doing being 30 weeks pregnant I need some time to eat and sort the house work when's sleeping. I was trying the cry it out to try sleep train him again which we have done in the past and it worked this time however he has resorted to screaming and trying to make himself sick and the most worrying is hitting his head against the cot. I gave in again coz I was worried he was hurting himself. But I can't keep doing this he's a busy toddler and the only time I get to do stuff is when he's in bed. It's been 2 hours now and he's still awake. I've given him Calpol earlier thinking maybe his teeth are playing him up. I just don't know what to do. Please if you have any advice