It’s certainly possible that this is about the stresses in your life. Sex may feel like one more demand on an already overloaded system. You may be wanting comforting and quiet reassurance more than the excitement and intensity of sex while you are sorting out other issues.
However, it may also be that you’ve hit a decision point in your relationship. Somewhere around 3 – 6 months into a relationship, people start asking themselves if this is a relationship that will last. Once the glow of newness has slowed down some, we take another look at the person we’re with and make another assessment about our readiness to commit. Sometimes people do this consciously. Sometimes it’s the unconscious that does the work. If this isn’t about your stress, it may be you are sensing that you’re not really ready to settle down or that there is something not quite right about the fit between you.
I suspect that a factor that makes it harder for you to do this reevaluation on a conscious level is that the two of you knew each other before you became a couple. You may think that you already knew what you needed to know and that there’s something wrong with you if you find something lacking now. That’s not necessarily true. Sometimes people love each other in a friend or almost sibling-like way; not in a committed lover-type way. The relationship is in fact loving, caring, and supportive but it’s not sexual. Maybe you tried out whether this friendship could be taken to the next level and have found that it can’t. If that’s the case, I hope you both can back off and still care for each other. Good friends are hard to find. There’s no need to lose a friend just because you don’t have the chemistry of lovers. I know it’s not always possible to mutually decide to put the brakes on but it’s worth a try.
Then again, if you’re not ready to commit to one person (and at only 25, that may be the case), then it’s only fair to tell your partner so. If he can agree that you two can enjoy each other without implying that you are getting ready for long-term commmitment, it might work. Or – if he’s the marrying kind – he might decide to move on.
I’m sorry not to be able to give you a definite answer to your question. I hope, though, that I’ve given you some useful things to think about.
I wish you well.