I don’t know what is the right thing for you to do. This situation is still so new to you and you are still assimilating it. But I do know:
1. That you would even consider paying his debts shows what a good person you are;
2. Part of you still loves part of him;
3. There is no moral requirement on you to pay anything-now or later;
4. You should not spend the next 18 years paying for his bad judgment;
5. If you pay-anything or everything up until now-make it the property settlement in a divorce;
6. Divorce him and ghost him.