You will not be able to cure this person. They have a serious illness. There is no point in living in that uncertainty. See a counsellor and start making plans to leave. You owe it to yourself to be happy.
Divorce is your decision because living with a manic depressive person can be difficult at best. I always believe (other than abusive behavior in a married relationship) that we are in marriage for the long haul. There is no guarantees as to which mate is going to become ill or with what. It's so easy to run away when things get a bit tough, but you sound like a strong person and want to make things work between you and your spouse and also you reflect being a made that is loyal.
Firstly, see your family doctor (your spouse doesn't have to go with you for the first appointment) and see what your options are. There are medications that can certainly help your mate over-come manic depression, but they need to stabilize on medications first in order to concentrate on the counseling that comes next.
CUT UP ALL CREDIT CARDS! Most Credit Card Companies want their money and would rather work with you to help you pay off your debts than not get the money at all. Write the Credit Card companies and explain the situation and then ask for a lower percentage rate on your outstanding debt. They will reduce the percentage rate (by law!) As long as you don't own an expensive home, own several cars and go on vacation, but you are basically just making it from pay check to pay check Credit Card Companies will work with you if you can pay the minimum payment with the new low rate of interest. This way you will keep your credit rating up.
Don't let your mate have ANY credit cards and give your mate an allowance in cash if it's possible. When I deposit my husband's pay check into the bank I know how much free money we have and first I pay our bills, then I put a little into an emergency fund and then I divide what is left between my husband and I. That's our allowance! Sometimes it's a good amount and other times we're lucky if we can take in dinner and a movie.
If you follow the above steps and get your mate in for proper medication and some counseling there is no reason your marriage can't become successful. If your mate refuses help then it's up to you to decide if it's worth the pain of going through all this and perhaps you need to move on. Make sure you make your feelings clear to your mate.
Good luck Marcy
In the US an adult (spouse or otherwise) cannot legally prevent another adult from using credit cards or obtaining other sources of credit unless said adult agrees, has granted a power of attorney or the concerned adult (spouse) has been awarded adult guardianship.
They cannot take the credit cards from the adult or destroy them or close the account without the legal authority or permission from the account holder even if the accounts are joint marital ones. To do so arbitrarily can result in serious legal consequences for the person acting against the non compliant spouse.
The best option for the spouse to protect herself is to consult with an attorney concerning the "innocent spouse" laws for the state in which she resides.