Maybe you just go to a bad school or maybe they became shit overtime.

Things didn't seem to be this bad in my days.

No matter what the case maybe, nothing can beat a classic teaching environment, if u got bad teachers then I would suggest you try to request a change of teachers if possible otherwise just keep asking questions and annoy them to hell, ignore if they scold you and keep on doing ur thing. You always have the 'complain to management card'.

The youtube channels are not bad and LearnoHub is quite good, but when it comes to marks they don't help you much. I would suggest not to depend on them too much and oly use youtube for troubling concepts.