Virtual contests. It's what you need and you almost never tried. Try this one and you'll improve your rating. (I'm not 1600+, but i broke my personal rating border by doing this)

A couple of questions: are you using the editorial to solve those 1400 problems? If so, then would you be able to solve a similar problem if it appears in a future contest? Are you practicing solving under time pressure?

Depends on what 1400 tasks you are solving.There is a huge difference between the new and old ones.Old ones a much easier and currently would be 1000-1100 rating

i dont think that im the right person to give you any advice, but, i have been there.

one advice i can give is, stop complaining and stop self doubt. Excelling at CP has alot to do with overthinking that too in a negative way. Stop overthinking, stop analysing this much. Just make your heat map as green as possible.

1. give all contests (something even i failed to do)
2. practice virtual contests (eductional will be great) + upsolve
3. use themeCP, a great resource for contest practice
4. move to next rating range once you get comfortable in it (50 questions is a good bar)
5. your indivisual practice has to be a mix of point 2, 3 and 4

make your codeforces as dark green as possible and enjoy this

You don't have to increase the difficulty of your training, just be sure that the problems you solve currently can be done by you (without looking at the editorial) under a good time, like 30 mins or 1hr maximum. So just be fast, and make sure to master binary search and greedy as well as basic number theory and solve many game theory questions and basic bitwise operations things.