Most Helpful Guy
I could be totally wrong so I'd like other people's input - but I'm guessing his interest in you dropped and he found someone he was more attracted to.
The cause of him breaking up with you stems from one thing and one thing only, which is this: the reason (s) for breaking up with you outweighed the reason (s) for staying with you. That's it.
This is why I think that he lost interest in you while finding someone else that he was into more. The reason (s) for staying went down, while the reason (s) for leaving went up.
"He says that he loves me but that he didn't see us moving to the next level"
This kinda seems like he wasn't attracted to you anymore. I mean, for me, if Rosie O'Donnell came to my door, I wouldn't be willing to go to any level with her. If Keira Knightley came to my door, I WOULD be willing to go to any level with her. The only exception in your case is if he was really into you, but had some psychological block preventing him from going to the next level with you. For example, maybe he loves you, but he can't marry (or whatever the next level is) anyone because of some trauma that happened to him as a child. I don't think that's the case here because (1) he was willing to date you for half a year (and therefore knew ahead of time that the relationship would eventually get serious), and (2) he's now dating other women. This tells me that he's comfortable with the idea (in general) of potentially entering into a long-term relationship. So the issue is his feelings toward you in particular.
One cause of this might be the fact that you two spent all your time together. Absence makes the heart grow fonder, and I think pacing the relationship to where you are not spending all your time with each other would have made the relastionship last longer.
Most Helpful Girl
He was completely honest with you. He enjoyed your company but he needs to be free to find the woman he wants to commit to. This is only being fair to himself and to you. He's wasting your time if he can't love you proper and waisting your time as well. Time to move on.