school is killing me

i go to school full time and went for nursing originally. i hated it. so i switched to mechanical engineering. i liked engineering in high school so i switched, but i'm afraid i'm going to hate it once i get later down the line, just like i did in nursing. i've already skipped most of my classes and am having a repeat of last semester, which didn't end well. i don't think my dream job would be one to financially support myself enough to save for surgery in the future or to move out with my boyfriend. it's all really stressing me out and i don't know what to do.