Conflicted

Ok so my boyfriend and I have been together about 9 months and I love him so much. He has just gotten so boring lately and I feel like he isn't putting in any effort into the relationship. I am so happy when I am physically with him but the second we are apart I question if we are really a good fit. I don't know what to do. I've talked to him about it and it'll change for maybe a day or 2 and then it's back to nothing. I find that it's hard to even come up with things to talk about when we have dinner together and he is always on his phone. I just don't know what to do I really do love him but I am conflicted.