Where to get clothes for smaller men?

I'm 5'5", 115 lb. As such, 30x31 or 30x32 pants are pretty fitting on me (but hard to find), but shirts are a travesty. I'm currently wearing a size 15 and it's pretty baggy on me. Judging by some of the posts here, this is really bad. But I just can't find any stores that have lower than 15 1/2 or 15. Thus my wardrobe consists of 15-15.5 and 32x32 pants. I look even thinner than I actually am. I have to punch notches in my belt.

Would not like to break the bank either. Any ideas?

EDITED WITH PICTURES OF A SIZE 15 SHIRT AND 32x32 PANTS

https://docs.google.com/open?id=0B5KsmWn2aJUFeklORDlPb0hYS28

https://docs.google.com/open?id=0B5KsmWn2aJUFZWEyVnh3blMwVU0

https://docs.google.com/open?id=0B5KsmWn2aJUFR0ZEX1RvWXRDSGM

https://docs.google.com/open?id=0B5KsmWn2aJUFVjlrel9nYkNmYUU

https://docs.google.com/open?id=0B5KsmWn2aJUFbG5TNWpEazcwM28

https://docs.google.com/open?id=0B5KsmWn2aJUFbF9ab2dhT3NiS0E

As you can see, these are VERY baggy on me. When I lift my hands over my head, I basically become the pillsbury doughboy or a ballerina.

With a measuring tape, I found out my chest is roughly 33". This correlates to an XXS or XS which begins at 34 (I doubt 1" will make that much of a difference).

How much does Cotton shrink in the wash? It seems that XXS may turn out to be TOO small if it's cotton.