A common mistake most newbies make is thinking that they need to have bunches of room in their boat. 
I've gotten in boats that 5'2 100lb newbies say they won't fit in and had plenty of room.  I'm 5'10, 155lbs, 10.5 feet, 32" Inseam.  
In fact, I'm almost your size and I haven't found many adult boats that I couldn't fit in. 

Try some thin shoes like NRS rodeo socks or desperado socks if you need to to get that little bit of comfort you're looking for, but most likely it's just a matter of not being comfortable with how most smaller boats fit.   Do you fit in without shoes on??