How are you sure she is bipolar? How long have you been married?
Divorce Remedy has a section on dealing with depression, read that section and MLC. Not everything is going to pertain to you, but enough of it will, especially about how to deal with the 'long haul'. You may be dealing with this situation for awhile and we are here to help you work through that.
That doesn't make it hopeless, it just makes it 'interesting'.
The thing I 'don't' see here, is what might be HER perspective of YOUR contribution to the marriage not being very appealing to her. The only thing I see is that she felt suffocated. What might you do to contribute to that?
When you read DR, you will see that DBing is all about changing YOUR OWN BEHAVIOR in order to change your wife's. The idea is that relationships are created by your interactions, which are behaviors. These interactions are cyclical, it really doesn't matter who 'started it'. You can, will, change your spouse's behavior when you change your own.