Dear M.,
First, you are absolutely right! It is NOT in the baby's best interest for him to be without his mother for ANY LENGTH OF TIME at this age. I know occasional "breaks" are acceptable. Parents all need a break every once in a while, but I have never been away from my child for more than a day within the first year and not more than 2 days within the first 3 years. The mother-child bond is so important. Father-child bonding is important too, but I think you would be doing far more harm than good by letting your baby go.
Second, Your boyfriend has no right to say you're being "mean". How childish is that?!?!? The baby is not a "thing" that he gets to play with while you're finishing college. Everything this baby sees, hears, and is exposed to, is making up his personality. He needs to be with you, as much as possible. If your boyfriend wants to spend more time with the baby, he can move closer to you or make the 2 hour trip for visits.
Third, you are absolutely making the right decision by not letting your baby go. I've read in some of the responses to your post that there could be legal consequences to letting the baby go. Please DO NOT LET YOUR BOYFRIEND MAKE YOU FEEL GUILTY OR INTIMIDATE YOU into doing something that just isn't right. Like another mom said, trust your instincts! You KNOW it's not right. No matter what your boyfriend says or does, if it doesn't feel right to you, you should hold onto that baby and don't let him go! You're boyfriend will just have to understand that you need to be with your baby, especially at this young age. And that doesn't make you "mean"...that makes you a good mother!