I can't move up from 400NL to 800NL - Please give me advice

Do you rely on the money? If so, this BRM is too aggressive.

If not, here's my advice: View it as a shot-take rather than a move up to a whole new stake. From this perspective, you're not saying "I have 25 BIs at 800nl"; you're saying "I'm comfortable having just 40 BIs at 400nl, so that gives me 5 BIs to take my chances at 800nl and be completely comfortable with losing." If that statement isn't true, you're being too aggressive.

From this perspective, the money's already spent. If you manage to not lose the money, then great!

(You have to be careful with the stop loss, though. You don't want to fire up another 6 tables when you're starting a session already down 3.5 BIs. The stop loss needs to be a worst-case-scenario, not a "stubbornly play 800nl until you bust the full dollar amount" benchmark.)

The other thing to keep in mind is you're crushing 400nl, so there's no rush to have that one shot-take where you finally stick at 800nl. What I personally do is everytime I hit my stop-loss at the next stake, I grind back up double what I lost so I have even more cushion for next time. This keeps you from going through an endless breakeven cycle by DONning all your earnings at the next stake.

I also recommend playing mixed stake sessions if you don't already. That takes some of the pressure off.

Finally, I would go easy on yourself. Your confidence is going to be very shaky at every stake change because you no longer have those 100s of thousands of hands as a winner to fall back on. You tend to look at every week, every day, every session and think "Can I not beat this game?!"

I'm a little skeptical you're playing way worse at the next stake, but even if you are, overanalyzing every losing session can create a feedback loop. As you grind up a bigger and bigger roll with each shot-take and get more HHs at the next stake, your self-critiques will either be disproven or you'll at least have a more rational basis for the critique; you have a big enough sample to say your 4b frequency's too low or your b/f range on each street is much higher in the new game, etc.

Until you have a rational basis for what the negging voice in your head is saying, it's just unfalsifiable noise.

Table select better. Check all of your lines where you check after an opportunity to bet as the aggressor and check that you are defending them correctly.

Wanted to give an update in this thread - It's gone a lot better and I've begun to figure it out