Why can I not improve?

As the title suggests I'm at a loss with this. I have tried for years to get better, understand different openings and recognize lines that I shouldn't do because they lead to a loss of material or position, I play the lessons, I play the puzzles, I watch videos, I review my games literally every time I can. I've tried longer time constraints and it only works against me because I will second doubt every single play I make because I have no confidence in this game.

At any point in time that I've been under the impression I'm doing well I just go on a multi-game losing streak, or I'm titled and forfeit 3+ matches in a row before I get pissed off and give up. Rinse repeat every day for about 10 years. I have played over many accounts and this account alone I have like 2000+ games and I've never been able to break 700 ELO. It just baffles me that the "average" is supposed to be 1000 for a new player, yet despite everything I've learned and practiced I don't even measure up to a beginner?

Every single game I have is either a landslide or I'm fighting every position and I can't see far enough ahead to avoid eventually leaving a strong piece vulnerable or forced into a bad trade. I've learned ALL the aggressive checkmates, and I practice the Ryu Lopez/Fried Liver Attack or Sicilian every single game. I hardly vary anymore because I need to know all the possible lines of at least two openings, and before I learned these openings I was STILL 600-700 ELO, and STILL struggling. So I'm genuinely at a loss for what to do. It's almost as if every single person is improving faster than I can, so that of all the people on Chess I'm perpetually stuck, feeling like I'm making 0 improvement and it's driving me crazy.

Yeah, I know what that's like. I think maybe just relax a bit, try not to do it so much by the book and just go with what you think is right, don't panic during games, just go with the flow. Chess is supposed to be enjoyed and from the sound of it it's not fun for you anymore.

It is completely understandable to feel frustrated when you put in so much effort and still feel stuck. The fact that longer games make you second guess everything means you are overwhelming yourself by trying to find the perfect master move instead of just playing solid chess. At your current level, you absolutely do not need to understand complex opening theories or stress over deep lines to climb the ranks. You just need to play basic, principled chess where you develop your pieces, keep your king safe, and wait for your opponent to make an unforced mistake. Stop putting so much pressure on yourself to play perfectly, trust your initial instincts if a move does not immediately lose a piece, and try to focus on just enjoying the board again. For more structured advice and substantial growth, look into the various classes we offer at our institute, Chess Gaja.

https://chessgaja.com/one-to-one-classes/

Honestly, I think the answer might be simpler than it feels right now. Chess improvement is almost entirely about consistency and time, not just the number of years, but the actual hours put in. Ten years sounds long, but if it's been casual or on-and-off, it can actually add up to very little focused practice.

I'm 90 days in myself. My first 40 days I was putting in around 5 hours a day, and after that settled into about 2 hours daily. That kind of volume adds up fast, and I've hit 800Elo with some ups and downs along the way. It's not a smooth climb at all. Losing streaks that made me question everything are just part of the process.

One thing I'd also gently push back on: learning "all the aggressive checkmates" and sticking strictly to two openings might actually be limiting you.