Did you check that axel bolt? Is the drive still lagging when you push forward of the sticks?
Some earlier feed back would of been nice!
The spindles are greaseless, you only grease to fill a cavity. I hope you haven't damaged any seals by over greasing.
I see you power wash under the deck. If you do that while the spindles are hot, they can suck in water which can cause problems.
If you want to wash under the deck, wrap some towel or something around the spindles first.
You did yourself no favours waiting a month to get this looked at, and still using it!
Just having that drive issue would be enough to get it looked at right away.