Perhaps try some tea, i.e. fennel for the bloating. Maybe something minty for the nausea?
Seriously, it can take awhile to stabilize. Stay calm and be kind to yourself. You're doing all the right things.
I had a thought re: bloating. Salt/sodium causes some people to bloat. How much are you using on your food? I agree with everyone that it may be too soon for Soy Crisps.
Are you taking a SFS? I take Benefiber and personally experience no bloating.
Also, you say you're not accustomed to eating so much FILLING and satisfying, healing soluble fiber so perhaps your body is getting used to secreting the proper enzymes to digest the food, so it takes time to realign your gastric/digestive juices. I take enzymes to help with this and it SERIOUSLY eliminates bloating.
Hang in there. It really takes time. I have IBS-D and I know that after a big time D streak, until I stabilize, I experience bloating. Also, if I don't drink alot of water, I get bloated.