Switching from Mechanical Engineering to Mathematical Finance & Economics.

So im in a really bad situation right now. I transferred after my 2nd year of uni. Im a junior now. Only 10.5 units were credited for transfer. After this sem ill have a total of 16.5. You need 72.5 to graduate. Anyway, i actually haven’t been admitted into the school of engineering yet. Im not allowed to take any of the engineering classes until ive been admitted. For now im taking courses like stats, physics, and programming that dont require you to actually be admitted into Engineering, but are required for the overall degree. Anyway, i found out after 2nd sem ill have no more subjects to take until ive been admitted into engineering in September. I was really planning to take a full course load of engineering subjects over the summer since im already extremely behind. Also, theres the added complication that some classes are pre reqs for other classes and some of these classes are only offered at certain times. However finding out that i cant take any classes over the summer really messed things up. I was planning to switch to mathematical finance & economics because you only need 60 units to graduate and many of the subjects ive taken will count as electives etc. i know people will say to stay with what you love, but i dont have the luxury of time and money. My parents are retiring soon and we still need to get 2 ppl thru college. If i stay with engineering it will probably take another 3 years plus 1 year mandatory Co op. Any advice? Thanks.