I'm questioning how collages will react to a drastic change in GPA

Best of luck at the new school! If you are able to maintain a 3.8-4.0 for the next three semesters (both semesters junior year and senior fall), you will definitely drastically improve your chances at getting into competitive colleges. As to what your chances are on getting into Depaul and other similarly competitive programs, this depends on a few things. First of all, having failed classes at any point in your high school career will make it rather difficult to get into schools like this. Second, how you did in your sophomore year is a bit more important than how you did freshman year. Admissions officers are often willing to overlook mediocre freshman year grades if a student's grades improved significantly after that. However, if your grades stayed basically the same or got worse between freshman year and sophomore year, that won't look so great on your application. Third, it depends on exactly how high you can keep your GPA this year and next. Think of your total unweighted GPA from freshman, sophomore, junior, and the first half of senior year combined. If you could raise that to a 3.3, that would be better than a 3.1, for example. Finally, it depends also on the other elements of your application. In particular, a good SAT or ACT score sent even to test optional schools will dramatically improve your chances.

Ultimately, though, it is important to be realistic with your chances. In 2020, DePaul's admitted class had an average unweighted high school GPA of a 3.75, and nearly the entire class had above a 3.5. Even with straight As, you probably won't reach this number (unless you didn't take many classes your first two years and you take tons now?). Admissions officers will likely be more lenient on you if you do have dramatically different GPAs from your latter two years of high school, but DePaul will likely still remain a long reach. This doesn't mean that you shouldn't apply! But you should also have many backup plans at less competitive schools. The best way to identify the kinds of schools to which you should apply is to use our chancing engine here at CollegeVine. You can input all of your information in your profile including the GPA you expect to have by your senior year, and we will show you your chances of acceptance at more than 1,000 schools in the U.S. From there you can build a list of safeties, targets, reaches, and long reaches that fits your needs.

Also, always remember that you don't need to attend the same college for four years! You could always transfer into DePaul, for example, after spending a year or two at a less selective 4-year program or after completing your associate's degree at a community college. This may enable you to save money, and will also mean that when you apply to transfer, your college grades will be more important than your old high school grades.