Sometimes when you have been in a relationship with somebody for a while, one or both parties can become somewhat complacent.
Your boyfriend may be telling you the truth when he says that he loves you, but he may just be very comfortable in the relationship, therefore he does not feel like he needs to make too much effort in order to maintain it.
Have you tried speaking to him about how you feel?
It may be a good idea to sit down with him and express your concerns. Alternatively, could it be the case that you are being too lenient with his behaviour, and perhaps need not over-compensate too much for the lack of effort on his behalf. If you do this, again he will feel like he does not need to make effort.
Alternatively, he could be going through something person that has captures his attention and is not allowing him to be fully committed to your relationship right now. Again, it is a good idea to explore this avenue and see where you can consolidate the situation. If this is the case, it wouldn't be fair to be too hard on him.
I hope this helps.
