Sounds like demand is greater than supply. A nice spot to be in for any business! Have you considered hiring help? Are you able to figure out a way to delegate some of the additional work and someday claim another day of the week?
I'm lucky in a sense that demand is high at the moment. I haven't been able to yet convert that to high hourly price, but it's high enough to actually have a 4-day work week.
I have considered hiring help and came to conclusion that I have two options:
A) hire an employee B) get another freelancer to help
As the demand is high it also means that hiring is also difficult for me. Front-end developers have plenty of options to choose from and that basically means that I should provide good culture, benefits, salary etc. which require lot of effort from my side to do properly. Also, hiring people in Finland is quite expensive due to the "overhead": insurances, pensions etc.
Providing work to another freelancer and taking a cut might be profitable when you've >3 freelancers working on a project you've successfully written contract for.
I am bit more towards karma thinking: if I recommend someone for free, the positive action will be returned to me when the demand is lower.