Hey, I'm 20 years old and in braces too.
I know it's hard to believe but your mouth
will get used to the braces. Does you mouth feel dry? If it does, the dryness isn't helping your mouth feel any better so in addition to the wax, use lots of chapstick and keep hydrated.
I had a lisp when I first got my braces on but it went away. I don't remember exactly how long it took for my lisp to go away, but I know that it didn't take very long. It was sort of like one day it just disappeared.
What have you been trying to eat? Stick to no-chew soft foods for the first few days until your mouth adjusts. Here are some soft food suggestions from this website:
http://www.archwired.com/soft_foods_category.htm The eating thing can be the biggest pain in the butt, I know. But you will be back to eating real foods soon. Personally, I find biting into anything uncomfortable so when I eat pizza (as an example), I cut it up and eat it with a knife and fork, instead of biting into it.
I hope you're feeling better about the whole thing soon!