I lived in a very similar relationship for 6 years and it was pure hell. I look back on it and realize I wasted to much time with him, I was seriously misreable and depressed to. Don't make the same mistake, already 4 years has gone. You can be happy and you deserve to be. Why sacrifice your happiness for some one who doesn't provide you with basic emotional needs? I hope you do find the couarge to do what you want and to leave.