Thanks for coming back and sharing your success! It's very inspiring for me. I just graduated with a Mechanical Engineering degree and debating going back for a CSE Bachelor's degree but unsure if it would be worth it.
I don't know how it is in other schools, but at mine you can get a masters in CS even if you didn't do your undergrad in CS. They just have you take the core undergrad CS courses, which is about 1-1.5 years of work. With an ME, it might not even be that long. You should look into that before going for a second bachelor's.
University of Hawaii at Manoa. I'm finishing up an undergrad degrees in CS and Business (started school at 30 after time in the military, so another success story for this thread), but I have a few friends in the masters program who came from other disciplines, which is how I know about this, though it's also listed on their site.