Your commissions keep the pot boiling and you are really starting to get good at them now so don't stop - when your business is on the boil never take it off the heat, it may not come up to the boil again.If the commissions are coming too fast, then that is your cue to increase your prices some more.
That should slow the commission rate so you can do other artworks in between without losing income.
What you can also do is space your delivery time frames so that you get the chance to do one of your own artworks here and there in between to keep the creative juices flowing and the to test other signature styles