Wow DE! I've SOOOO been there. I'm two years out of the initial physical separation (the divorce took 16 months because of all the financial issues) and whereas I still have those sad and guilty feelings from time-to-time, they are not nearly as intense or frequent as they were in the first few months.
Much like you, I am a professional, I am responsible with money, and yet we STILL ended up in BK. I trudged through it and thought it could be a new start for us but as soon as we were out of that immediate emergency and I got things under control, he was out racking up more debt behind my back. I found out about that and an affair in one day (I was actually looking for Rx drugs and found a loan payment book and suggestive texts from a woman instead) and I was DONE. It still floors him that I could just walk away, but the truth is that I had been so incredibly lonely for a partner for so long, I really had emotionally walked away long before that day.
I will forewarn you that even though have clearly made your decision (a wise and healthy one, at that), there do come times of weakness and uncertainty. I have learned that a journal really helped me. I kept a good account of my thoughts and his actions so that when I felt those moments of weakness, I could revisit the strong and resolute "me" and remember why I made the choices I made.
My kiddos and I still have to deal with some BS that comes from his continued poor-decision making but I have to remind myself that at least it isn't every day and that because *I* am free of his insanity, I am a more stable parent for them than I was in past years.
Hang in there!!! You sound like you are clear and determined and you'll get nothing but support here.