What are you having a hard time with? You need to be more specific for anyone to answer your question.

With bipolar there is a tendency toward heightened sex drive in the manic/hypomanic phase and a decreased/non-existent sex drive in the depressive phase. Of course these are tendencies and I would think they may even reverse in some people. If you are having a problem with maintaining an erection it may be a function of a medication-- many antidepressives have a side effect in this area. I recommend discussing any problems in this area with your Dr. Additional medications may be helpful for you.