It incredibly common for overweight women to lose weight when they get pregnant, and it doesn't mean that you are starving your baby. I don't think that forcing in excess calories that you don't feel like eating sounds very healthy. In fact, you only need an extra 300 nutrient dense calories a day for pregnancy. Eating till you "feel like you're going to burst" in order to prevent weight loss sounds like a sure recipe to aggravate your current digestive issues and potentially cause even more issues (heartburn?). If you are worried about your food intake, you may want to try using an online tracker.

I would make all of your calories count (super-nutrient dense stuff) but not add gross excess. Just get plenty enough protein, I think the Dr. Brewer Pregnancy Diet recommends about 100 grams per day, and you can make it as LC as you want.

We are all different, but for the record I'd been LC for about 6 months before we conceived, and by then I'd lost down to 179. I ate pretty much the same for my whole pregnancy, with a few extras like a couple pieces of low-cal bread for massive bacon sandwiches and sweet potatoes more often. Getting lots of protein was never a problem for me, and my calories had always been high with all the fat + protein. I didn't intentionally add food for the sake of doing so, I just ate what I felt like eating, which was still a lot. I continued losing (actually faster than my usual snail pace) till I hit around 168, I think, then at some point in the 2nd trimester I started gaining. I checked in at 191 pounds to deliver, and that was going more than 2 weeks past due.

This is a very emotional and exciting time for you. Trust that your body knows what it's doing so you may be able to relax and really enjoy your pregnancy. I wish you all the best.