How many sick days is too many?

So, at my school we are allotted 4 personal days and 12 sick days each year. The sick days roll over to the next year if they aren't used, the personal days don't. I usually take about 10 per year BUT this year has been particularly challenging for me between being sick and just needing mental health days because my kids are so bad this year. So far, I have taken 8 sick days and 3 personal days... and it's only March! There is no way i'm going to get through the rest of this year without taking some more days off. This job is fucking exhausting on top of the 2 other jobs I have to work to make ends meet. So my question is... how many days off is too much? What's your opinion?