Confession: I'm only with him because...

This hurts so bad to say but I'm slowly falling out of love with my boyfriend of 3 years. I use to think age doesn't matter yet the 20 years age gab between us is starting to get to me. I'm going to be honest, the main reason I'm feeling this way is because we don't have sex anymore but he watches porn and jerk off every single day. I tried talking to him about it but he doesn't seem to want to fix it.