First sorry about your morning sickness T., *hugs*. I went through that with my son and it is tough. I can't imagine now with a toddler too.
My son is also 18 months. He has his front 8 teeth (4 on top and bottom) and he too has his molars coming in. So he hasn't been eating much lately besides breastfeeding. I have found that not worrying about it is the key. I try a few different things but if he's not up for eating, we try again later. He always has a sippy cup of fresh water available to him. Also, we have carpet picnics for lunch where I put a table cloth on the floor and we eat there. Then he's free to continue playing and zooms by for some food when he's ready.
Here are some things that work for us: peanut butter sandwhiches cut in shapes, steamed mushrooms & peas, beans & boiled chicken combined with taco seasoning and a little cheese (this is a huge hit), yogurt, kefir milk, cheese, soup, kiwi, banana, strawberry, grapes, mango, raisins, scrambled eggs, fish (talapia or orange roughy), Goldfish crackers, Juice Plus gummies (although these are his supplements, he loves them!), jello, pudding, frozen cubes of juice and basically anything that I'm eating. If I take a bite, then he is much more interested.
Good luck!