How are you going to pay for the dream school for even one year? The maximum loan you can take out is $5,500 your freshman year. Your mom has to co-sign everything beyond that, and she said she can’t/won’t help.
How much are the other schools where you have acceptances?
The dream school for one year would probably be a waste in that you risk having all the debt and no degree in the event you get in over your head and can’t afford to apply to or deposit at your transfer school. Bad situation.
Your mother is in the wrong for not talking about finances earlier. Some people overestimate their chances at a scholarship or simply make hope their only plan. Unfortunately it didn’t work out, so you have to play the cards you were dealt, not the hand you wish you had. Seek out cheaper options, make the best of it, and maybe save the dream school for graduate school.
It will turn out okay.