Originally Posted by tuckster
the boat might be a little tight but you should just get your roll down
I disagree with the people who say "you should just get your roll down" or "tight is good." Especially if you're a beginner, you want to be able to pop out of your boat easily. When you're underwater and possibly caught against a rock or log or in a hole is NOT the time when you want to have to do contortions just to get free of your boat. Plus, if you are worried about not being able to get out of your boat, you probably won't be as confident and you won't enjoy your time on the river as much. And the whole point of boating is to have a good time.
Try sliding the seat back or removing some of the foam. If that doesn't work, try a different and maybe newer boat with a bigger cockpit.
After not boating much for a few years, I've been having similar problems with my Wavesport Siren, and I'm thinking I'll re-learn with the Eskimo Kendo that I first learned in while I look for a better newer boat, maybe an EZG. It sounds like I have a similar build to you: I'm about 5" and 140 lbs.