The halving has so far occurred after the bottom of each market cycle was made so based on that (next halving May 2020) the new bottom should take place inside this February - April.
What is even more important than that is the lengthening of each cycle, which seems to trade on an arithmetic progression. Approximately 583 days are added to the length of each subsequent cycle. Needless to say this affect the duration of the bear cycles as well, which also progress on an arithmetic mean (252 days).
This shows that this time the market cycle will take long to reach a peak that should be in by August 2023.
I think your analysis is more accurate, because you also take into account that BTC becomes slower, as it grows. Which makes sense, since BTC behaves in many ways like a physical system. The more mass it acquires, the more inertia it has, the slower it becomes.
So yeah, excellent chart, and keep up the good work :)