Help!

My boyfriend and I have been together for almost two years. We are crazy about each other, we are about to move in together and we are talking about engagement. But, recently he has been acting very weird. He tells my dogs to shut up when they bark, he has been rude to me, and he curses at me and is very mean. I don't know why he's been acting so rude. He hasn't been putting my feelings above his, and he just simply hasn't been the man of my dreams. I don't want to end things but I don't know why he's been acting so different. Please help!