I'm the same way I'll be 8 weeks Monday. So now when I eat I just eat small portions all day long. Just try to find that something that doesn't make you feel that way. I eat a lot of grapes and yogurt.
It's possible that it can be gas or bloating. This is my 2nd baby and I feel pain and discomfort which I didn't have with my son. I drink Perrier water seems to help relase gas/bloat. I hope it gets better.