Not to add to your distress, but if you're not telling him how it makes you feel, you're not being honest with him. That's no way to go into a marriage either. Set a time limit *for yourself* to see if he proposes, then leave.
Been there, done that, let me tell you: better to leave on your own terms than let him string you along. I was in a similar situation. We were living together, but he wasn't moving toward marriage. When we decided to change apartments, I started looking for my own. I made the mistake of telling bf, and he got all sad and started "oh,you're not going to give us a chance" b.s. So we moved into a new apartment, and three months later, he told me he wanted some space and asked me to move out. The stupidest part was, we didn't actually break up, but obviously we weren't together, either. The relationship limped along for another year, until I figured out he was sleeping with other women when I wasn't there (duh) packed up my toothbrush and change of clothes from his place, and left.