I understand. I had a boyfriend for 6 months and we got along great and had fantastic chemistry. One morning I woke up beside him and I couldn't stand him. I was repulsed by him physically and annoyed by his personality. The poor guy did NOTHING wrong. It was like some physiological switch had flipped, and all of a sudden I couldn't stomach him. We broke up soon after, and it was truly "it's not you, it's me". He was a perfectly wonderful guy, and I can't explain why this happened.

This was the first and only time that ever happened with a partner, and to this day I can't explain it. I'm sorry that this isn't helpful advice, but I do want you to know you're not alone.