Just two months ago I thought I finally had it, but today it feels like I'm starting from the very beginning...
When you think you had it, write it. Write a set of rules.
And weeks, months later, read them again when nothing works.
Did you apply them religiously?
Yes => your rules need to evolve. Analyze what didn't work during the last cycle. Maybe your rules are valid in a bull market, not in a bear. Maybe your rules fit trending markets, not trading range. Maybe your rules are too complex and difficult to apply in volatile markets. Etc.
No => discipline problem. Take a break, trade less money but apply your rules religiously. If your rules fit bull markets, trade only bull stocks/sectors/futures. Discipline. You will gain self-respect, self-confidence (and money

).
In my case, when everything goes wrong, i reread my rules and 99% of the time, I notice they are still valid. I take time, solve non-trading problems (family, friend, colleagues, health...), trade less and I regain confidence.
Common mistake is to think that former rules were false and you want a revolution, change everything. And you can spend your entire life searching for a perfect method which exists only in your dreams.
Generally, your rules / methods are still valid and you "only" need to change your mind. Easier said than done.
CM