Lump w/Burping

Hello -

I sort of feel like I'm going insane right now because I have all these seemingly unrelated symtoms (symptoms).  I've had an inconsistent dry cough for about a month, accompanied by headaches.  The cough produces nothing.  In the last week I've had sinus headache (pain centered behind my eyes) and a thick plegmy post-nasal drip; this tends to happen to me when it gets cold outside and I am exposed to the dry indoor heat.  

But all of a sudden, today I have an intense headache behind my eyes, some heartburn and nausea, and what feels like a slice of bread rolled in to a ball of dough stuck in the bottom of my esophagus.  

I'm a nursing student so I know a little bit about anatomy and physiology, and I've read that this lump may likely be an over-tightening of my esophageal sphincter.

Can anyone make sense of these symptoms?  I would have written off the cold symptoms to changing seasons, but this lump in my throat is grossing me out.  I eat 6+ meals a day and I have no appetite.

Thanks!