It is an unfortunate truth in any relationship that once the initial spark of that relationship fades, it is tougher to maintain the same level of passion and interest in each other. If you’ve been with a girl for a while and you think your girlfriend has lost interest in you, rest assured that you are not alone in your problem.
The first thing to keep in mind when trying to face your doubts is that this may not always be a bad thing. Sometimes, the passion, interest, and intimacy that is found in the first moments, weeks, and months of a relationship are simply unsustainable. At some point, you simply have to start being more independent, or you will start to see your work suffer and perhaps lose friends. Even if the interest level seems non-existent, it might simply mean that she is now much more comfortable with you, has settled into a routine, and that she has not put as much effort into seeming very interested in you.
However if you are having these thoughts, chances are there is a certain amount that you are missing from her in this relationship – even if it might be a good thing that she is feeling more comfortable with you (if this is the case.) The first thing to do is try and look at yourself and what you are doing. Have you been taking her for granted? Not putting enough effort into the relationship? Have you been skipping steps in the bedroom (neglecting foreplay, for example), not bringing anything to the relationship, not telling her you love her enough, and not making her feel appreciated and special? Has it been a long time since you last took her out on a date, or did something just the two of you? If you see that any of the things above are in fact true of you, then your worries are probably true, and probably based at least partly on you; perhaps there was a gap between how great of a boyfriend your girlfriend thought you would be early on in the relationship and how great of a boyfriend you actually are.
If, however, you do not think that your worries have to do with anything that you are doing – you yourself are putting forth enough effort into the relationship, into making her feel special and appreciated and into spending quality and romantic time with her – than chances are it is simply that she doesn’t appreciate you, or simply that you are not right for each other. If this is the case, there is not much you can do – and it wouldn’t be worth it even if you could. Many times, your relationship might have been held together by the initial excitement that existed during its beginning, and without it you realize that the two of you are perhaps not so great for each other. This happens, and when it does it is best to move on to someone that will not lose interest in you after a while; rather, someone who will let their relationship with you evolve, in a good way, as time goes on.