Can someone confirm that I'm ill from milk?

So last night I had a glass of milk and then got into bed. I told myself that it probably wouldn't make me feel good but I love milk and I have braces so I can't drink anything acidic like juice or soft drinks. I'd have had water but I was hungry and I thought that milk would fill me up better. So I went to sleep. I had a terrible nightmare and woke up about 6:30 am. I got up to go to the toilet and when I came back to bed I felt disgustingly nauseous. I can't take the dream off of my mind but I'm sure that the sickness is coming from the milk. I looked it up and saw that milk can curdle in your stomach overnight and lots of people get sick in the morning and throw up the chunks. So that's what I'm sat in the bathroom trying to force myself to do. Only I can't. I just keep burping up air, but the air stinks. Any ideas or advice? Do you think it's the milk, or could it be the dream making me feel awful?