What is wrong with me?

I haven't noticed this until recently: I get this weird tightness felling thing in my chest on certain occasions. it first happened when I heard from my friend (he is in a wheelchair) that discovery was going to do a doentary on him. Me having OCD, I was logically beating the **** out of this thought over and over in my head for the next few days. Eventually the tightness dissipated. And recently (Today) when the discovery camera crew came to film. He invited me over onto the set and I was surprised that I was going to be on TV. But I got that sort of tightness in my chest again. What is it? Jealousy, mental stuff, by body reacting weird to random things? what is it?