Throwing up/ spitting blood 0.0

Ok so I have been recently rediagnosed with ADD so I have been put back on concerta (I took it as a child) however I've been having dosage changes to try to find what works best. Anyways, as a side effect of concerta, I'm never hungry and I've actually lost almost 15lbs since the beginning of September. I still eat, I just can't handle a lot of unhealthy good like pizza and buffalo wings. So, tonight, I was really hungry because my meds wore off so I had a lot of pizza 0.0 I ended up getting sick and throwing up, but there was a good amount of blood along side it and when I finally felt better, I was spitting out blood for a good 10-15mins >.< I don't have a loose tooth or any cuts in my mouth either. Any ideas as to what's wrong with me?