I'm so sorry. I actually dated a man who had bipolar disorder, but he did nothing to help himself - counseling or otherwise - and it was very frustrating.

It's ok to have doubts about the future, and feeling the pressure to get married when you don't know if you're really ready is a huge decision for anyone.

The best thing I think you can do now is try to help yourself. Understand your illness, and encourage her to try to understand too. Go to counseling, perhaps go together. Maybe that would help.

In the meantime, I really think you should focus on your well-being before you take the step of looking out for the well-being of others. If she really loves you, then she'll understand this.