Re: am I too short?
You can't fight genetics, but making sure you have a proper diet can help. Don't know about the exercise, but I supposed being fit helps too, although I've heard that certain things, like bodybuidling, can actually stunt bone growth.
As for you being 'too short'. You are below the world average, for a full-grown man (but you're not doen yet) and also slightly below average for a 17 year old. Height charts usually indicate that by age 17, you've done most of your growing, but don't stop completely until about 20 years old.
But those are just statistics. Feeling like you're too short is just an attitude. There are lots of really attractive 'short' guys around. For example, here are some guys who are 5'7": Tom Cruise, Eminem, Kurt Cobain, Robert Downey Jr., Emilio Estevez...