My first question is :Do you meet with your counselor one on one as well? If that isn't the case, I would ask that you meet with your counselor by yourself. It sounds like you could use some guidance and assistance in your feelings and thoughts on leaving your husband.
My second question is : You say your husband is Bipolar, but on medication. You also stated that he does have anger issues, and you are afraid of how he would react to you wanting to leave. Has he been physically abusive? Are you worried that this will happen if you tell him you want to leave?
If this is the case, I would advise that you definetly need the support of a counselor and friend to help you leave him.
IF it is not the case, I think it is best that you approach this with him when you are meeting with the counselor. It is best when dealing with someone who has mental health issues to always have another person there to mediate and assist in helping them deal with situations. Especially when they come from a family member or spouse.
I also want to mention that if you are having these feelings because you met someone else, then you need to rethink your feelings entirely.
If you have felt this way for sometime prior to meeting someone else, then you need an outlet to express how you feel, and how you should deal with your feelings and thoughts on leaving to your therapist.
I don't have much experience as far as the needing an attorney, but I think if their are children involved you most definetly will need one.
Is their a person or family member you can confide in to help you in terms of living arrangements? Are you involved with a church?
You shouldn't have to convince your husband of anything. If you want a job, get a job. You have every right to live your life. Bring this up at your next counseling session. At least you will have someone else there to listen and offer advice, and to also let your husband know your thoughts and feelings.