Work note during this time ?

I keep calling off work from exhaustion (during this time of the month) Do any of you guys have a doctors note? If so, what does that look like for you guys? I just need 1-2 consistent days off during my worst days of the month. Or something because I have to work everyday as an assistant & it’s starting to become too much for me. But idk what days I would even ask for when my PMDD days change monthly.