How do you study chess and actually improve

I have been playing chess for hours a day for the past 4 years now and feel like im not getting any better, I typically play 3 minute blitz games and literally cannot move past around a 950 rating (most of the time I am rated lower than 900). How am I supposed to improve my rating/actually get better at the game? I have tried things like

- Analyzing my games

- Doing puzzles

- Playing against opponents much better than me (I always get stomped by them)

None of the things I listed have helped me at all, how does analyzing your games make you a better player? How do puzzles? If anybody could give me advice it would be VERY appreciated. 

Please don't post useless replies like "Just play more", a more in depth comment would be more beneficial.

Keep doing the tactics puzzles, but really study them ... Only attempt to solve the problem if you think you see the entire line and all of the variations. If you don’t see all the variations, then after your attempt to solve, go back and play through all of the computer’s possible responses (and I do mean ALL of them) until you do see them, even if you got the answer correct in the first place. Rinse and repeat ad nauseum for the next several years.

3 minute blitz is next to useless. Don’t waste your tactics time.

What mode should I play then? 5 minute blitz or 10 minute rapid?

The longer the time format the better for learning. Personally I really enjoy bullet and 3 min, but because I wanted to improve my game I forced myself to play 10 mins. Ideally if you have time, even longer formats like 15 min are even better. Since you have more time on longer formats, you have luxury of exploring all options instead of relying on bad habits and instincts.

Do tactics and when you are sick of doing them, do more. And when you are sick of doing those, do more. And when you are so sick of those that you want to quit chess forever, hire a psychologist or motivational speaker to encourage you to keep going and then do more.

I don’t play much but here is what I think might be considered standard game-playing advice: Play 2 slow games per week (at least G30; retire from any game with less time than that). Analyze each game whether win, loss, or draw with opening explorer, opening book(s), and an engine for your earliest (opening) and largest (tactical) mistakes. Keep an eye out for the first move you miss that puts you “out of the book” of your first suboptimal response to your opponent’s first move that is also out of the book. If you can afford, collect pgn’s of your games and hire a coach to more thoroughly analyze your games.

Spend most of your time studying tactics thoroughly and not playing, since most of your mistakes now are going to be elementary blunders and missing your opponents’ missed elementary blunders. A coach is better for after you get past that phase of visual neglect and missed tactics that are only 1-3 moves in depth.

This is gonna make me sound stupid, but what do you mean by "tactics"?

Tactics are move sequences which can used to either win material, gain a positional advantage, or bail you out from an opposing attack. Some examples of tactics include: discoveries, pins, forks, skewers, x-rays, and many more. Basically positional patterns that you should be looking out for in your games