I think it's different for everyone. I wasn't really sick with the first three, but this time around I was sick for the first 4 months. I ate a lot of cottage cheese with fruit. It was the first thing I ate every morning. Normally I'm not a big fan, but, for whatever reason, that's what sounded good. I found that I had to eat quite often to help with the nausea. Now I'm able to cut back on the frequency.
This is going to sound ridiculous to you, but I swear I have better digestion when I have bacon several times a week. I do get the "uncured" variety from a local market, and it says it has no nitrites or nitrates (which, remember, are naturally occurring in many veggies). Maybe if you could get ahold of some good quality bacon? I have bacon with eggs and sauerkraut as often as I can. I don't know if you can do kraut, but that would also help with digestion and elimination.
Pregnant and nauseous too... :P
I am about 6 weeks pregnant with my 5th, and feeling really nauseous. I find myself wandering around the kitchen knowing that I need to eat before the nausea worsens but struggling to find something I can stomach. This morning I had a boiled egg with salt and pepper on it, and then apple slices with different cheeses on top. I try to have eggs and bacon and fried tomatoes some days, though I never want to start making it so I have to make myself or ask my husband to if he has time. Once I am eating it, it tastes good and feels fine afterwards. I would say try to get as much fat as you can to keep your blood sugar stable, and satiate your appetite to control the nausea as best as you can. For me eating doesn't make the nausea go away, but keeps it from getting unbearable. Sigh. A nice way to get some protein is to have a salad for lunch or dinner, with some eggs, meat, bacon or fish on top, and cheese, avocado, etc for fat. It tastes fresh and smells good and you're getting some protein too. Just a few thoughts. Hope your nausea passes soon, with my 4th I felt ill all the way through, though looking back now I think I had developed an actual allergy to wheat at that point (which last year manifested as swelling and weeping skin around my eyes, and propelled me into primal eating almost accidentally).
I know what you mean though about sometimes eating something thinking I'll feel better and ending up with a gurgly, horrible stomach. Every time I accidentally eat something with vegetable oils in it I get a bad stomach. One thing i have found SO helpful this time around is carbonated spring water. I love the stuff, it really helps settle my stomach and keep me hydrated because I find it easy to forget to drink enough, and I am very prone to kidney infections in pregnancy if I don't watch how much I drink.