OMG, I'm so HUNGRY. HELP!

I'm just about 18 weeks and my appetite has kicked in like insanely strong. I'm still feeling nauseous every day and I need to eat pretty simple foods (Not a lot of spices and seasonings). Even after eating a normal sized dinner, I get extremely hungry before bed but I have zero interest in eating even though being hungry makes me crazy nauseous. SO what can I eat at meals times and for snacks that is VERY filling? I'm not worried about eating too many calories since I'm still below my pre-pregnancy weight. BTW, I'm also vegetarian if that makes a difference in suggestions.