You can get intermittent leave with the PFML but I don't know what they cover for mental health. You'd have to check with your doctor to see if they would complete the medical portion of the paperwork for you.

You can get paid for only taking a day or two off in a week. I used the leave on a part-time basis after I had my son. I was able to get paid for the two days I was off on leave, and I worked three days. Each week you submit a claim of how much you worked in that week (they get information from your employer about how much you typically work in a week), and you get paid for the time off that you took. Since I was using it as family leave, I was able to use it throughout the first year of my son's life. I don't know if you have the option to extend it that long for medical leave.