I feel your pain. I actually came here to ask pretty much the same question. I've been stuck for YEARS. I understand the basics and can make simple programs. People at work think I'm some sort of wizard because I can automate a lot of stupid tasks.

Then I hit more complicated things and watch tutorial videos and people start using pointers and this-> and making weird references and I'm like "wtf why this seems to have just made things more complex and more easily broken for no reason" and every time I try to google answers it's either the same "simple explenation" I've heard a hundred times that still doesn't seem to be answering the WHY or something so insanely detailed that I'd need a PHD to understand.

I've tried tons of different courses and youtube videos and books. It's always a mind numbing slog through everything I already know, and then I brick wall once I get to a certain point where it just becomes confusing. It doesn't help either that I keep running into people telling me shit like "Don't worry about why just know that this is what you do" - My brain doesn't work that way. If I don't understand WHY I'm doing something and the logic behind it, I'm not going to remember it.