pretty awful?

I've had a horrible stomach bug since Thursday, spent the best part of Friday throwing up at work yet my boss still wouldn't let me go home to suffer in peace. I even puked blood when i got home which wasn't cool.

Seeing as he'd seen how ill i was Friday i kind of hoped he'd understand me not coming in today, instead he had a big go at me over the phone and started going on about another ongoing medical problem i have and how this is becoming far too regular (my last sick day was about two months ago, although i did get sent home just over a month ago after collapsing at work.) He even wants me to try and come in this afternoon. :(

How should i deal with this without crying in front of him/throwing up in his office?