>>12752399for linear algebra, try Hefferon's "Linear Algebra", it's free, has full solutions, and he even put up a complete video class on YouTube. I worked through it a few weeks ago and I highly recommend it.
I don't have any good blanket recommendations for the rest, but what worked for me was, whenever I didn't get a certain thing working from the textbook/lecture notes, I'd search YouTube for a good explanation of that one thing.
You might also want to check out Coursera, edX, and MIT OpenCourseWare or however it's written for video lectures, sometimes you'll find a good course exactly for your topic (rare, but possible - or you'll find one video from the course that explains whatever you're working on right now).
Other than that, maybe spend more time reading math books and getting familiar with them, you'll get better as you do it more and the other anon is correct, no YT video can replace a good textbook. Godspeed.
