It sounds to me like the honeymoon phase is over. You speak of college so I take it you two are quite young. You say he's a nice guy so maybe being just friends might work better? If that's not an option just ask him "what's up?" It sounds like he is stressed about some things. Maybe he just needs a little breathing room and a good night sleep. Communication is key so just sit down and ask him if any things wrong. Couldn't hurt!

Dx: BP2, PTSD, bulimia/anorexia
Risperdal 4mg
Trileptal 300mgs
Buspar 45mgs
Ativan 1mg PRN
Vyvance 70mgs PRN