My husband has been lying to me about his credit card balance. I confronted him and he said I'm being crazy?

My husband is 30, I am 27. We have been married since Jan 2010 and we have a daughter who will be 1 year in September. Last May, my husband opened a Capital One credit card (0% interest for the first year) and we used it to purchase a nice camera which was about $600. In January of this year, I began asking him what the balance was on the card. We'd been paying $50 a month toward it since May 2010. He told me it was "a couple hundred dollars" and said that he'd cut the card up so he could no longer use it. I asked again about the balance a few weeks ago and got the same answer. Last night I signed on to the Capital One card website and found out that the card is maxed out (at $750) and has been maxed out for months. But when I make a monthly payment of $50 each month, that gives him another $50 he can spend on it. He did not cut up the card- he has been using it the whole time without telling me. When I confronted him, he said it was because I'm always nagging him about how he spends money. I feel inclined to mention he has filed for bankruptcy prior to our being married (yes, I knew) and the charges on the credit card were mostly for fast food and for DJ equipment (he DJs on the side and has a business acct for that but runs out of business acct money and used the Capital One card to cover expenses.) He feels that he's not doing anything wrong and that I am overreacting and being a nagging wife. I feel like I've been lied to for the past 7 months and am starting to question whether I should have married this person. Thoughts?