3 year cough - really could use help

I’m trying to get help with a definitive diagnosis for a chronic cough that I have had for about 3 years now.  Sorry that this is so long but I want to detail everything I can remember.

Prior to 2005/age 25 I was very healthy.  I rarely was sick my entire life, exercised and tried to eat healthy.  I was 6’ 160lbs.  Around mid-2005 I went through a difficult divorce for about a year during which I developed a terrible cough.  The cough was extremely forceful and produced copious amounts of mucous for at least four months.  I remember the mucous being clear, yellowish, greenish, and eventually tapering out to whitish.   My abs, back, everything hurt.  

I know that severe depression can cause havic on the immune system and I would say I that 2005 early 2006 was very traumatic for me.  But I have been very happy since mid-2006 till today.

My ex-wife and my two male children who were 8 and 9 all developed a similar cough around the same time frame leading me to believe it was infectious.  Shortly after my 8 year old was taken to an urgent care and had a chest x-ray with a diagnosis of pneumonia.  My kids both got better but for the rest of 2005 my ex-wife and I still had the cough.

I went to an urgent care and Dr.’s office at least five times throughout 2005 and early 2006.  
The first visit in 2005 was that I had irritated my lungs causing them to produce excess mucous and it could take up to six months to go away.  
When I came back again, I was given a chest x-ray but told that nothing was wrong, yet my symptoms were still horrible.  I was told to give it more time
The next time after that I think I was given a nasal spray or something.  
On my last visit for this condition I was given an inhaler to see if that would help.  It didn’t.

Eventually my ex-wife stopped having the cough in early 2006.  For me it got a little better but never fully went away.  For the most part the cough has lasted into an un-productive cough.  Occasionally I have gotten white or yellowish sputum but that may have been from a cold or flu – it’s hard to say.  Cold foods make it worse sometimes.  To further complicate a diagnosis, some foods cause the cough to come on more strongly leading some to think I may have food allergies.  However, I have never had an allergy prior to 2005 so I’m not buying it for now.  I changed my health habits too, eating mostly organics, fruits, green tea, no fried foods, making food at home etc.  No change.

I went to an ENT in late 2007 because I read that I may have sinusitis, post nasal drip, etc.  The ENT stated I have a “massive deviated septum”.  That made sense because my whole life I have had a “stuffy” feeling nose that hurts a little when pinched.  It made me wonder from all the crying and such in 2005 if I messed up my sinuses somehow and got a chronic nasal infection.  The ENT did a cat scan of my nasal area and recommended surgery and maybe allergy testing (allergy testing makes good money as I understand it).  I am considering the surgery to fix my nose but I want to get a definitive diagnosis about my cough and make sure my lungs are ok.

My biggest fear is I that was misdiagnosed in 2005 and now have Chronic Bronchitis or worse.  My cough has more or less stayed the same but in the last 6 months I have occasionally had moderate sharp pain right where my rib-cage converges above my heart.  I sometimes feel very slightly out of breath, but I did pass a health fair lung test with flying colors.  I eat very healthy and weigh about 175lbs, but I’m not really exercising as much I as I should.  

I’m really hoping someone could give me some advice as to what this might be based on what I have written.  Also, what specific tests I should get to make a firm diagnosis would be helpful.  I have great insurance so money is not an option at this point, getting the answers and getting better is all that’s important.  I’m 28 and feel like my health should be much better than this.

Other History:
I have never smoked, rarely drink alcohol (cup of wine a month or so).  I have never taken any illegal drugs (honestly).

My mother has had severe asthma since childhood, but other than that there are no major illnesses that I know of in my family.  Sinus issues are somewhat common on my father’s side.  My half-sister just had a sinus surgery to correct a deviated septum.

I take no medications.  Health wise, the only thing is I have had done is extensive dental work done over the last 10 years including a few infections, extractions, and many root canals (sadly).  I wasn’t the best patient with taking antibiotics, so I imagine I am probably resistant to Keflex and other similar anti-biotics.    I have never had any surgeries or major illneses except for this one.