Pencil portrait for book cover

Done this portrait of Robin for his course material cover.
This is the education whch I have been helping him to run since early last month.
From corporate image - logo design, letterhead etc., revamping website (not fully done yet), advertising, marketing, blogging, to registration and signing up for course etc.
Those are what have been keeping me busy these months, besides my own drawing business.
Working till late in the night, around 2am+ and wake up early in the morning around 8am+.
As what I told my friends - my chair is my wheelchair. I sit on it for more than 16 hours a day.
The remaining time is for running errands like fetching my son from school, and daughter from in-law's place, getting lunch and dinner. That's all. The rest of the time is on work. Very pathetic, and unhealthy, I think.

My clients asked me to go to their offices for meeting. Sorry, but I can't afford the time.
I know they are not happy, and they don't believe that I am that tight up.
I have no choice.
I need the time to travel to and fro, for drawings and other admin works.
I have to let go these clients, and I can only take in jobs for those who are willing to place their order via emails.
And when I told them usual leadtime is about 4 weeks.
They can't believe it. No choice, but this is the fact, as there is a limit on the number of drawings I can do in a day.