Recently i've been feeling rather uncomfortable especially in the throat/chest area.
It feels as though there's trapped air in it and even when i burp, it doesn't seem to do me any good. Sometimes i think i'm having breathing difficulties, sometimes i think i'm just over-reacting.
This has been going on for about 2 weeks?

I think this all started out when i went on a trip 2 mths ago. From day 1 of the trip i experienced a very very bad aftertaste in my throat whenever i ate. Also i felt as though i could not breathe properly and felt light headed at times. I visited the doc and apparently he says that i have phlegm trapped in my lungs. While taking the phlegm medication he gave me, i noticed that i never coughed out any phlegm at all.
But when i came home after my trip, i felt totally fine so i assumed that maybe i had travellers' sickness.

I don't know if i'm suffering from any panic or anxiety attacks,i sure hope i'm not, i'm only 23 and i've never experienced anything like this before. I also smoke but i've been cutting down alot ever since, so i'm not sure if smoking was the cause of this.

Also i noticed i've been getting like little sores on the side of my lip which i thought it was due to opening my mouth too wide. It's usually one sore, which looks like a tiny hole, at one side of the lip. It usually stays around for about 4 days, goes away and come back again like a few weeks later. Are this symptoms all inter-connected?

I don't know what to make of this and i'm a little paranoid about all these. Please help, i don't really feel like myself anymore.