Feeling hopeless

Hi everyone I am new and newly diagnosed I have not had the breathing test yet but did have it 4 or 5 years ago I don't know the score but they put me on inhalers at that time..I have always thought it was chronic bronchitis as I use to get a cough every winter that lasted almost all winter..I have not had any cough for the last 3 years..nor do I have any wheezing doc seemed surprised but said my lungs sounded good.i am scared out of my skin as she said I have 6 months to 2 years to live! I'm 60 and of course not ready..I've been a smoker (a pack a day) for about 45 years..I've been struggling to quit since the first part of the year I have stopped completely since the diagnosis. I've never been an exercise person but I'm trying to add walking for at least 20 mins to my day and hope to work up from there. I don't eat good pretty much nothing green never have and I didn't drink water I am now still learning what I should eat. Also as for oxygen she did order oxygen and suppose to be 24/7 but I have not been able to use it like that one side of my nose clogs up and the other runs like crazy..also I cannot lug these huge tanks around when I do have to go out,she said my state ins would not pay for a portable so I will either be home bound or not using it..my oxygen level was 83 last week but 2 weeks ago it was 89 I know 89 is not good but if I add water excersise and eat better maybe I can get it up on my own? Maybe 83 was just a off day? I have never been hospitalized with any of this which is a good thing from what I understand.any advice would be greatly appreciated. Oh and how do you handle the total anxiety some times it washes over me so much it really takes every thing I have just to put one foot in front of the other. Feeling very hopeless