Not so sexual anymore.

Angel • I cant get my messaging working on here so add my snapchat silver 4321 or Instagram angel.baby410

I am 17 going on 18 in April, is it normal to go through a phase where you love sex and then it just dies down after like 6 or more months? Because my boyfriend I have now I know I'm sexually attracted to him but not in the mood as often as I was before I started dating him. We have sex like every month but only 1 or 2 times and I feel bad about it but does anyone think it could be because we started living together now? I know married couples stop having sex so often so idk I'm just wondering if it's a phase? I didnt know if it could be a living together thing to the point it dies down or something?