Lungs.
 

I don't know why but every now and then I get these sharp pains in my lungs that hurts when I breath that has started this past year. It isn't every day or so but every couple months. About a couple weeks ago I got that painful feeling that literally I am breathing in flames and I felt something pop literally. It scared the crap out of me. In the past walking at school I have gotten that feeling and I drank water and it took it a while but I felt better. I have been worrying about it. My dad had asma but I don't so I am not sure what the heck is going on.

I used to smoke everyday or so about 3 cigarettes but it went on before that for a while.

Oh and I only smoked for a little less than a year.

The breathing in fire could be stomach acid. Try drinking milk next time it happens an see if it helps. certain foods such as spicey foods can also set this off.

I can't drink milk. :-/ and I have a highly sensative mouth so I don't eat spicy foods.

Might be worth speaking to your doctor as they can prescribe (or you can buy them over hte counter) ant acids which can help prevent this if it is acid that is causing it.