Reddit mentions of An Introduction to Modern Stellar Astrophysics

Good to hear! Might I suggest then An Introduction to Modern Astrophysics. You might be thinking, "well, that's just a general astronomy book", and you'd be right, but it also contains within the entirety of this book. I'd recommend it anyway, as it's the standard undergraduate astronomy text. It touches on pretty much every field in astronomy you can think of, however briefly, so many people keep it as a reference well past their undergraduate careers.

This may be a bit of a challenge to get through if you're at the Calculus 2 level. Some of the math goes quite beyond it, such as differential equations and Fourier analysis, but I'll trust you when you say that you have an aptitude for math.