Dance partnerships are a very different type of relationship. If you break up who will you dance with--your teacher?
If you are near a major city with plenty of ballroom teachers and aspiring students--then you have more options. But if you live in a smaller area--it's more difficult. Long distance partners usually don't work for long-- it's hard to practice with them and dancing together often is not an option.
I have had an on and off again partnership for seven years and at times she really gets on my nerves. Recently, I've just disregarded the negative stuff and tried to give her lots more posative feedback hoping to curtail some of negative. It seems to have helped some.
Getting and keeping a good dance partnership together is not an easy task. It could be easier if your skills and motivation are about equal. If one person in the partnership improves more or is more highly motivated--then this is a good reason look for a new partner. The psychology stuff probably could be worked out if your dancing is still improving. After all, it's the quality and improvement of your dancing that most are reaching for.
Lots of things can sabatage a dance partnership. For example, career changes, kids, dance goals, jealousy, long distance, money, fighting, aging, teacher problems, and injuries--to name a few.