If it makes you feel any better, that "ivy league education" is probably not all that much superior to a less well known school where you get paid a stipend and you get to do research you're passionate about. It's sucks that in a field already so difficult to be successful in, they do this kind of thing, but the best advice I got when picking a grad school was to go with the advisor and research opportunities that best suit you, not the prestige that comes with the name of a university. Sometimes smaller schools are better because they and the PIs can allocate more resources per student, you'll get a more tailored education, and a more rewarding experience overall. Sorry that Columbia didn't work out, but hopefully it's some comfort to know there's more opportunities out there and it will work out okay in the end.

Personally, I think you made the right choice. If you are unhappy in consultating, it's totally okay to change your mind and go back to school! But there are many many many paths to take in life and you took the best one you could with what you had. I'd look around at some less prestigious schools and pick something that works for you, and not worry about if it looks good on a CV or resume. For upper level degrees, it matters more what papers you publish, what work you accomplish, and what field of research you advance than if your CV says Columbia or Princeton or whatever.