I am so sorry to hear about your situation. It sounds like your husband is either going through a major bout of depression or is just a jerk. It sounds like he has energy though, since he is playing sports and traveling, so perhaps it isn't depression. And his wreckless spending behaviors started a long time ago. But he may have some mental health issues that need to be addressed. He is on meds, but it doesn't sound like he is getting any therapy to help him develop better coping mechanisms. A good first step would be meeting with a psychiatrist who can make sure he is on the right kind of medications, but medications are not the only solution. He needs to learn how to deal with life in a more positive way through self-help books (doesn't sound motivated enough for that) or a counselor.
If I were you, I would ask him if you and he can visit the psychiatrist together. Tell him you are concerned about his well-being and love him. Just like if he had cancer, you would go to the doctor with him, you should also do this with him, if he will let you.
You should also encourage him to find a job or get enrolled in school. Get the newspaper and start circling opportunities for him. Encourage him to get a job doing something that he is passionate about, even if it is just part-time. He likes sports for example. Could he get a job at a YMCA or another organization that is sports-related? Make sure he knows that you don't expect him to go back into the corporate world, but that he needs to do SOMETHING. Perhaps it would be a good time for him to go back to school. UCO has great Kinesiology programs.
I think a deadline in this situation is good. I had originally said 30 days, but in further consideration, I think a six month timeframe is better. He will need time to correct his path. It took him 7 + months to get this off track. Make sure he knows that you will be fully supportive until May 15th, but after that, you are done.
In the mean time, I would start getting the house ready to sell, unless you think you can afford the payments on your own. Talk to a lawyer to learn your options. Take away his credit cards, remove him from any bank accounts, and start a family budget. In that family budget, he will get a certain amount of "fun money" and so will you. If he can't have enough fun on that, maybe he will be more motivated to get a job. Make sure the budget is not a punitive thing. Every family should have one, and you just need to get started now.
I promise that this situation is not good for your son. You may think that the best thing for him would for you to stay with your husband, but your husband is not modeling good behaviors and is not making you a happy mom. Stick with your counseling and be strong. It is time for your husband to grow up and make good choices about his life and his family. You love him and will commit to another six month of being his biggest cheerleader and friend, but after that, you can walk away knowing that you did everything you could to help him get back on track.