The gushing flow of love soon slows down when you come a long way. Those first moments are exciting and obsessive. But all this will soon come to an end, that's what makes love valuable.
Maybe you don't feel butterflies in your stomach when you meet your partner now. You may receive less intense vibrations now.
Is that because you are no longer in love or he is not the one you were looking for. Do you feel you are bored of this and you want new?
Let me tell you the truth, no matter how intense your first moments of love were they all will settle. Your relation will get secure with time. And you won't feel that intimating love for long. Whoever the person is, your long-term relationship will make you take him for granted.
There is no definition of a perfect relation, you create your own and your partner creates his own. Maybe sometimes you will go through loyalty test in your life with no preparations.
I know it's hard to explain yourself to someone when you are just not sure of your thoughts. But it's just fantastic when you have someone who is not judging and supporting.
Even if your love is fading, just take your time to understand that this is just the absence of excitement. Don't give up, make it healthier.