The right pace is not always the fastest one available.

Sustainability sets the pace, not capability. You can nearly always go faster than you should, and the cost shows up later as exhaustion, sloppiness, or a project abandoned two-thirds through. The right speed is the one you can hold for the length of the thing you are actually doing.

Ask of your current pace whether you could keep it for a year. If not, you are not moving fast; you are borrowing. Adjust down to something you could genuinely sustain, and accept that the finish line moves further out. Arriving is worth more than the appearance of speed.