Hello Maherovic!
Weocome to the CP forum here!
I noticed reading through your post that you're seeing a Dr for the phlegm problem and he is scripting med's out to you for it? So, you have insurance right? If so the MRI you mentioned should be covered by them. Or is there some sort of a co-pay I don't know about?
Pain in you're chest can be a serious problem, and is nothing to mess with. It could very well be a warning sign. I have cramping in my chest from time to time, and it worries me as I had a massive Heart Attack back in 2002. I do suffer Angina as well, but the cramping is related to my neck problems DDD, and I can adjust my body to stop it dead in its tracks.
I think you may have a good idea, and may want to visit the Gerd's forum for the throat problem.
Again welcome, and please do get it checked out if you indeed have insurance.
SE