What does it mean when a guys says its not you its me... my guess its really you

Yep.. Pretty much right there. It is a way to let someone down without trying not to hurt the person. There is an outside chance it is them. Maybe he realizes that the relationship is asking for more than what he can give or want to give. Can work the other way too. Without knowing exactly, I would give the reason the benefit of the doubt and count my blessings that I am not in a relationship that is not working.

What you said is absolutely 100% true sometimes.