Thanks for the wealth of information
How to get better while staying free?

You can go to your local public library. They have free internet and you can also borrow chess books. Some of them even have chess sets available.

I go to YouTube and watch videos on the Danish Gambit and other openings, because there are a lot of good people there who will explain things without charging you.

Who told you that? I disagree a lot. It's a gambit, so you start by losing a pawn but it's a lot of fun even if I lose.

Interesting free option
Just made an account there and my man, those are some really long courses. The shortest one I could find was 50 minutes, the length of the average TV special. that just goes to show the complexity of chess.

Also, no need to play so much. Overextension will do nothing but hurt your proficiency in chess(speaking from experience here) my lowest rating I have ever been at was when I played 50+ games every day. Don't overextend yourself. Play at most 10 games every day. That helped me get out of my lowest ever rating.

I can give some tips.
NUMBER 1: Limit your speed chess. Give yourself time to practice the tactical/positional/strategical ideas you just learned. Then, later on, you can practice how quickly you can see those patterns with puzzles, and you can loosen your limit.
NUMBER 2: Your mom was right when she said "kids these days". We have all the information we need with one click of a button. Chess.com isn't the only chess website (no matter how much the devs seem to want you to think that with Lichess profiles not being mentioned in GMs' bios and being unable to mention other chess sites, namely Lichess, but that's another conversation for another day). You can learn some really valuable stuff from YouTube, Twitch, Chess Website (ya don't say?), Chessfactor, Lichess, etc.
NUMBER 3: Puzzles, puzzles, puzzles! These help you spot patterns faster in real games so you can see stuff like queen sacrifices that lead to a mate in 3 in a matter of seconds if you stick with them for long enough! 15 a day, doesn't matter where they're from, is my recommendation.
NUMBER 4: Openings, Endgames, and Middlegames are crucial points to study. Openings are a teaser to how the rest of the game will play out, middlegames are where most of the action of the game takes place so you should know how to ride the waves of chaos, and endgames are where it all ends (obviously). There are several types, such as King + Bishop + Knight VS King, King + Rook VS King, King + Queen VS King + Pawn, you get the idea. Most of your games will reach the endgame, so you need to know how to checkmate your opponent with just 2 bishops/1 bishop and 1 knight/other mating nets.
NUMBER 5: Have fun! This is the most important step to improving at chess. Normally, people think of developing your pieces and controlling the center (you should do that) as advice, but remember: Every once in a while, ask yourself, "Do I really enjoy this?" If you don't, you can save yourself a TON of time studying chess when you don't want to when you can be studying what you really want to do with your life such as medicine, programming, etc.
If you want more tips, hit me up on messages.
Normally I don't join that many more chess.com clubs since I've been cutting back on them, but I'll join this one. I'm always open to learning new things