No one can count on getting an internship at those wages (and we don’t even know if OP would be majoring in the right field for that anyway) nor can you count on getting some large scholarship. Sure anything is possible, but the OP must deal with what is probable. Hoping for a good job and scholarships to make that kind of money does sound crazy.
As for backing out on the ED. Technically, you can back out if the FA isn’t enough. But one shouldn’t do so lightly. You’ve run the NPC, you know what it says. If the FA comes in anywhere close to that I would say you are ethically bound to accept. Besides, if you know it’s not likely to work, why bother? Sounds like a waste of time.
OP - what are you going to do if you can’t make ends meet? Withdraw? Take on more loans? (You can only do so much without your parents cosigning)…Don’t set yourself up this way.