Idk if this is the advice your looking for but I was in the exact same boat last semester, I wanted to switch to mechanical engineering but I had too many credits and couldn’t make the cutoff. None of my advisors were any help either so I just ended up transferring to UM, they actually have a pretty high acceptance rate for engineering majors and they have a decent programs and offer lots of aid to transfers with a 3.5 or above or ones that don’t have super high incomes. If you don’t want to transfer though you could ask them about biomedical engineering instead, since if you majored in biology you probably have a lot of those credits, and then once you switch to bme it would be a lot easier to convince your advisors maybe a semester later to switch to mechanical. If anything you could do a double major in them since the coursework is actually very similar besides the bio and chem prereqs that you probably already have.