Me & my bf can't help but argue during my period (Need Relationship Advice)

I have a boyfriend of almost 2 years now. Back then when we were still new to our relationship, everything seems fine whenever I'm on my period because we rarely make time for each other. We'd talk for a couple of while or date once or twice a month, we were still distant from each other. But when things start to progress, when we started opening up more, even about my periods, we can't help but get into an argument whenever it's that time of the month. This started around the first year of our relationship.

I'm 20, not on any form of birth control but whenever I'm on my period, my PMS attacks me. Suddenly I have mood swings, I'm pretty irritable, anxious, easily stressed out, highly sensitive. Plus, my cramps kills me and I feel so tired most of the time. This would last for a week or less than 10 days, then afterward I'm back to my usual self. But during those 10 days, I can't help but feel so emotional, I'm so sensitive to simple things, especially when it has something to do with my bf. Sometimes, I'll get offended over small things, like if he calls me fat, I'd be sad pretty quickly and he just doesn't understand me, and he finds my actions unreasonable. We keep on fighting over small things during my period because he takes my mood swings seriously.

I'm not blaming everything on PMS. I try my best to control it as best as I can, but there are times that it really gets over me and I can't help but feel certain things. If only I could just remove it from me, I would because it's ruining my relationship with my bf.

In the meantime, I'm on the last day of my period, and we're still arguing about the simplest thing. I don't know what to do anymore. I tried to explain to him that I could get pretty emotional and crap during my periods. I even explained to him how PMS works, but he just won't get it. Any advice?