Don't worry, he's not. Once the initial excitement of getting a girlfriend wears off its what all boys do. It doesn't mean his feelings toward you have changed its just he feels as though he has fully 'got you'. It depends what makes you feel like this, if its that he is paying less attention to you, you have got to loosen the reins or do something that gets those sparks flying. Also make most of the time you have together because you never know what could happen.
Sometimes couples break up because they don't feel like it was how it was before. You need to do something that will spark it again. Because if you both love each other, then it is worth fighting for truly. All that it is is boredom.
(Lizzie helped me with this advice)
Ps~ this is perfect.