First of all, thank you so much to everyone who responded. I really appreciate it.
After reading some of your responses, I thought I should clarify a few things. He closed the line of credit without ever taking any money out (because I caught him). When I did catch him, he said that he had no idea why he did it because he knew the potential consequences but it felt like a compulsion to keep it secret from me. We also only have one joint account, that we never use. We just split our bills in half so I don't ever see what he spends. I see things that show up, but there is probably more than that. Actually while I was out of town, I got a letter from the bank that held the joint account asking me to update it because there had been no activity on it. Last I knew there was almost $6k in there but I assumed he had taken it. I was shocked when he hadn't.
He never blamed his mom for any of this. That was my own guilt thinking I should be more supportive given his awful childhood.
He actually is a good dad. He spends time with the kids and obviously loves them, probably to the point that he identifies more as a father than a husband.
I think that's it. Thank you all again.