help!

Ok I'll be 5 weeks tomorrow and for most of the past week everything I've eaten makes my stomach hurt doesn't matter what it is. Fresh veggies or pizza doesn't seem to make a difference. Also everything gives me diarrhea. This is my first pregnancy and I'm at a loss for what to do. Any ideas as to why this might be happening? Also I need ideas for snacks that help with morning sickness. I'm gluten and lactose intolerant and gluten free crackers are expensive so crackers are out, what else worked for you guys? Thanks!