<human>: Could you distill the essence of the text into 1-3 sentences?

I simply don't know how to act around her anymore. She hasn't initiated sex in 4 months, and if I initiate it, she doesn't seem very into it. I think that over time has begun to wear on me, and make me question a lot about myself. I've asked her about it and she always has some sort of reason why, but I know deep down that if she wanted to she just would.

She seems loving in general, but I wouldn't go as far as to say I feel like I'm the man of her dreams. I care for her very much, but I feel like with us getting married in 6 months, that this is a strange phase to be going through. I feel like we should be bright-eyed and bushy-tailed about being around one another, and it's just not the case. I certainly feel that way for her, and I've shown in many times, but it's not reciprocated so much, so I feel like I need to curb it. Thus leading to me not knowing how to act, and generally just being quiet around her.
<bot>: I fear this relationship is ending, or she's cheating (how can she go so long in our youth without sexual desires?), and it makes me very sad.