Dear Tammy,
You are on the right track as you wonder about the solution. Yes, you'll have to let him cry it out, so to speak. It'll break your heart a bit, but remember that you are not hurting your son by doing this - you are helping learn a very important ability (i.e., to fall asleep on his own).
http://www.askdrsears.com/
My son is 14 months and still wakes up many times. Some babies are just more sensitive and are just wired differently. It sounds like you may have a high need baby and Dr. Sears has good information on high need babies.
Good luck, I understand how you feel.
Cheers,
Rachel