Congratulations!
Talk to your psychologist about what it takes to have a successful marriage and family with BP disorder. Read about this as much as you can. Figure out when would be a good time for *you* to get married -- e.g. perhaps you want to be more stable, figure out a working course of treatment, etc. Hopefully your fiance will be supportive of that. Help your fiance help you, and make sure that he knows as much about BP as you do.
Some articles and books:
Bipolar Dating & Marriage -- Romantic Relationships
Marriage and bipolar disorder | bphope
The Bipolar Relationship: How to understand, help, and love your partner: Jon P. Bloch, Bernard Golden, Nancy Rosenfeld: 9781598699678: Amazon.com: Books
http://www.amazon.com/Loving-Someone...77ENF7Q0EVHMST
Living With Someone Who's Living With Bipolar Disorder: A Practical Guide for Family, Friends, and Coworkers: Chelsea Lowe, Bruce M. Cohen MD PhD: 9780470475669: Amazon.com: Books