nausea

My first pregnancy I had verylimited morning sickness, this second time around I am nauseous pretty much all the time. The only way I feel better is to eat, i hear about so many people that go so sick they can't eat. All I want to do is eat to get this horrible tast out of my mouth and this feeling out of stomach. I m so worried about gaining too much weight. Anyone else experiencing this type of nausea?