I hate to say it, but working EMS, even part time, generally isn't possible if you're taking full time college classes. I was able to work "per diem" in college, working one shift a week. In retrospect I'm not sure I'd do it again. I slept through far too many classes, turned in far too many assignments late, and used EMS as the excuse far too many times. There are some college EMS programs that have crazy requirements too. College is great, EMS is great, but I'm not sure they really go well together.
Online classes are great for those in EMS, but if you're a traditional student, then you'll want the college experience that in-person classes provide. In college I did a mixture of 95% traditional classes, 4% online, and 1% hybrid (online classes with proctored tests). After a semester of college and EMS something had to change... so I did college full time and EMS even less. I worked vacations and over the summer to make up for it.
If you're working in EMS to help pay for school, I'd find a different job. I know my friends working in the school's cafeteria made almost as much as I did. They walked a few hundred feet to work, while I was driving nearly 100 miles. Their schedules were flexible, where mine weren't. They had it great, while I was doing a great job, that turned out to be counterproductive towards my college efforts.