Overly stressed & anxious?

I'm a very stressed person, I would say. Last night, something came up, and my stomach started turning, I felt nauseous, I want to puke but I get nothing. When I eat, my stomach hurts and I feel even more nauseous. I've been sleeping, and napping to de-stress myself but it's not working. Sometimes, there would be times where I would just start crying and punch myself over and over again.. then I'd be fine. Then it would happen again, and I would start punching myself again. Like a cycle. It happens often when I'm overly stressed and anxious and sometimes when I've cried enough, I feel light headed enough to faint. The last cry I had was 30 minutes ago, and I saw myself get a knife and hold it, I wasn't going to cut myself or anything.. I was just holding it and slicing my stuffed animal. I kept playing with the gauge making my fingers go purple and release it. I don't know.. I don't know what's happening, I always become like this.