Fizzling

Me and my boyfriend the sweetness romance kindness everything is fading. He wont talk to me he wont smile he avoids looking at me use to send me sweet things before bed now it's goodnight go to bed and that worries me cause he might not need me anymore and that hurts me. I don't know what to do cause when I ask him I always get yeah I'm fine or yeah I'm okay. I get short answer like okay yea fine nothing ok and nothing more unless he's growling at me and he says shut up and other things. I cat confront him he'll snap and get angry I don't go through his phone I let him have space I'm really relaxed with him   But I don't know what to do.