This depends entirely on the kind of content you make, your audience, etc. The "once a day/week/whatever" metric isnt one size fits all-- I've posted 2 videos, almost 2 months apart, and im over 200 subs pretty organically. But my content takes a longer time to execute than say, a vlogger, and if i tried to go faster i would absolutely get burned out and the quality would suffer. From a general professional perspective, if you recognize you're getting burned out then your current schedule is not sustainable and you absolutely should adjust for what works for you. I assume you're doing youtube because you enjoy it and it would be nice to grow an endeavor you like spending time on. So if you wear yourself out on it and stop enjoying it, what's the point then? It becomes like any other grind. 2 weeks is still pretty frequent from my perspective. Give yourself the space to make something you're proud of while still being attentive to your own needs.