Without knowing where you live, and therefore not knowing the laws governing your situation, plus the fact that I am not an attorney, I will only be able to give you a general response to your question.
You should try to find out how that particular cult deals with such a situation. You can try doing a Google search to find others in the same situation. Since you didn't mention the cult, I can't help much with that.
What I can suggest is that you try to have a discussion with your husband. Communication is always important in any relationship. If you have already come to the end of your desire to save the marriage, let me know that. Let him know why. Let you know how you feel.
Listen carefully as he responds. See what his feelings are. See if he understands that his involvement in the cult has damaged your marriage.
You need to determine if he still loves you and if that love is strong enough to appreciate your feelings. If not, and if he makes that really clear, then divorce might be the only solution so that you can move on with your life.