The chest tightening is indeed the lungs starting to clear themselves. Once I had given up I spent about the next six weeks coughing up what appeared to be a large tabby cat in small portions. ......
Your incentive bike purchase is a fantastic idea (apart from the fact it's a Trek
) but best of all will be the fact that you will be able to ride it with the benefit of oxygen on board.
Your first day back at work will have shown you that you are no longer enslaved..... forced to huddle outside with the rest of the lepers. This was one of the biggest and most surprising benefits for me... we had no outdoor smoking area, and I had to put a coat on over my uniform and walk at least a block away from the station to have a smoke.
Other health benefits... I used to get a cold, then it went onto my chest, then I had catarrh for about three weeks. I reckon I would get a cold every two months or so. I gave up 30 months ago, and haven't had more than a bit of a sniffle since I gave up. What could be described as a cold has been a bit of a runny nose for 24 hours,, then nothing. My overall health has improved.
The sour taste is a typical symptom. My dentist explained it was a change in the acidity balance, and lasts for about 8 weeks (though it does diminish) try chewing a bit of gum.