Oh jesus fuck.

Your best bet might straight up be Khan Academy. Here's the calculus playlist. I used this and an AP Calc prep book to teach myself in high school because our school didn't offer it.

Watch videos 13-37 for derivatives, and 58-76 for integrals, and then 85-91 for sums/series leading up to Euler's formula which is possibly the most useful piece of math you will learn as an engineer. After that, I actually really liked the MIT OpenCourse DiffEqs lectures. Take copious notes. Pause and rewind a thousand times if you have to. Each video is only 10 minutes long, clock out like 5 a night and really grind on them. Find worksheets or textbook problems.

Trust us when we say that integrals and DiffEqs are not light prereqs. Unlike some classes you cannot fake it til you make it. If you don't have a very solid understanding of it, you're fucked. Within a week or two you'll be doing variable transform integrals of imaginary numbers. But if you follow the above and really commit to it basically every night for the ~5 weeks you have, you should have some decent understanding.