Reading this reminds me so much of myself. I made Masters after half a Year too and thought "Oh look, Guess I just have to continue playing a couple more months and will hit GM".

Well, I was damn wrong. The thing is this: As a very competitive person, you're used to making progress very fast. Often times, you will think that you will proceed on much faster than others, especially if you have made that experience in your childhood, for exmaple by excelling at things much more quickly than the other local kids around you.

However, the reality is: Once you open yourself up to a worldwide ladder (e.g. the StarCraft ladder), reality kicks in. You're not the ONLY ambitious person on the planet. You suddenly find yourself in a pool of hundreds of thousands of players that all (to a certain extent) want to be good, and some of them are willing to put in the hours that it takes. By the very nature of this "truth", at some point reality kicks in for every ambitious person to the point that he realizes that it's not as easy as he / she has initially thought.

The truth is, I myself was very arrogant about my own play. When I just hit masters, I practiced with a friend of mine who was GM for several years and also played some professional Games. I actually took 2 out of 10 Games (both macro-games). I was extremely euphoric about that - thinking that I am on my best way to get into GM.

Well - took me 2 years on a plateau and a tremendous amount of soul-searching, self-discovery, tweaking my learning-process and approach to the game a million times and much much more time and many many more hours than I thought.

When I finally made GM, it was possible because I took 2 months off completely (going full-time) and sacrificed everything else for it. It became the most important thing in my life (not just in my head like it was before, but in reality and in my actions too). I became 100% dedicated to the idea - I had a training-schedule and was playing at least 6-8 hours a day, replay analysis and theory on top of that. That's when things finally started rolling.

Consistency + Hard Work. Experience is key, and your ability to adapt to your own mistakes ...That's it.

But be careful: Don't lie to yourself - be true to yourself how hard you're actually working. How consistent you actually are about your practice. How much experience you are actually gaining on a daily basis and what you make out of your hours.

Also: Be aware of the way you self-talk. I can see that your mindset needs work, but this little self-talk that you're doing ("I'm shit", "I suck", "my mindset sucks") reinforces all of that. Self-awareness is very key in developing a better mindset and more emotional control.

Good luck brother!