You don't want to stay in range; you get hit to much that way, even if you are a defensive wizard. It is best to stay just out of range, only come in to punch, then get back out. Staying in gets you involved in endless shoot outs.
That's the purpose of the first round, or, at least, the early part of it (if you are fighting 3rds); finding out how long his arms are. Stay just outside that reach, use slips to get inside, throw punches, then get out. When training you should practice getting out every time you work at getting in, and never stand still after you punch- see the recent Montiel/Donaire fight.
I think that maybe if you learn to NOT stay in range it will ease up on your nerves some. When you are out of range you don't have to worry about punches because they have nothing to do with you- when he move in, you move away, don't wait for the punches to start hitting gloves and arms.