Made a major mess

I don't want to be the girlfriend that's super rude when she's PMSing, but yesterday was a horrible day for me: I have a sore throat, cramps were really bad, and a huge headache to top it off. My boyfriend was hiding stuff from me, apparently he wrote some things about me that he knew I really wouldn't like, and I wanted to know what it was. He always tells me that there are no secrets between us, so I was pissed that he only said that when he wanted to know something from me, and so I ignored him. Only, he didn't want to be ignored, so he kept pestering me in the hallways, and up and down the stairs. People were behind us, so I gently pushed him along so we could get out of other people's ways. He lost his footing and sort of fell down a step, and he was hurt, saying "I really could've gotten hurt. I could've died." And of course my idiot self said "As if I would care." The thing is, I know I'm young and all, but this guy is the reason I wake up every morning and can't wait to go to school. He's helped me through the tough times, the ups and downs of my bipolar disorder. And I would surely care if he died, because he really is my life source. I don't know how to mend this, so hopefully someone could help me.