It’s hard for me to remember how long I spent on the fur, my guess would be between 5 and 10 hours in total. I used 5 different hair systems, (the head, the arms, the legs, the white long hair all over the body, and the vibrissae).
At first I used vertex groups to drive the density, length and clumps of each system. Then I spent most of the time grooming the hair (adjusting the curve and length of single particles). The most challenging part was definitely the head.
In the end I had vertex Color driving the colors of the hair and vertex groups driving the clumps (with children set to “interpolated”)
I think you have to accept that things will be ugly at first, and then you spend time refining it through multiple iterations (you can see how the fur evolved on the breakdown on my Artstation)
I hope this helps