Hi M.,
How old is your son and are you still breastfeeding? I ask because he may have been going through a growth spurt. When babies do that, it is important to feed them often in order to keep your milk supply up and to make sure that they get the nutrition they need. They usually need to eat every 2-3 hours (my daughter decided to eat every hour one time AHHHHH). If your son is just a few months, I'd advise against making him wait too long...maybe 10-15 minutes max. If your son is older, say, past 7 months, making him wait a little longer isn't a problem so much anymore. I would suggest try ing to soothe him back to sleep when he is up in the middle of the night. But if he really wakes himself up or just doesn't go back to sleep ypu may wantt o feed him. I started bringing my daughter in bed with me so that she doesn't wake completely up. First I do nothing and see if she rolls over and goes back to sleep, then if not I try to rub her back and sometimes hum. If that doesn't work, I'll nurse her. If she nurses in the middle of the night like that, she usually falls right back to sleep. Sometimes they are just hungry. Other times, it is the sucking that will help them fall back to sleep. My daughter hates pacifiers, so she doesn't use one. Of your son will take one, you can try that as well.
I hope this helps some....I certainly feel for you and your sleep interupted nights. Either way, it will get easier with time.
Take care.