Panick attacks go hand-in-hand with OCD. I think it sounds like you are having a panick attack. My sister vomits when she has a panick attack....when I have a panick attack, my chest hurts, i see spots, sometimes I pass out or sweat and hyperventillate. I just downright shut down. Vomiting is a very common side effect of panick attacks. Maybe you should look into it... also, have you ever considered meds for your OCD? I take meds. I feel like God led me to taking them. I love my meds.