With all the joys of motherhood, and there are a lot of them, there are also some real drawbacks. One of those could be a decrease in the time you get to spend with your partner, just the two of you.
Mother's Day doesn't have to mean treating only yourself. Spend some sans-kid time with your significant other -- no working, no phone calls, no refereeing. It can do wonders for your relationship just to have a dinner together when you can talk, just the two of you. It can have deep, long-lasting benefits. You may find yourself making a habit of it.
And finally, treat yourself to some commiseration.