I'm really sad to hear about the cancer

That is a major bumber. I can't address your health problems and I wouldn't like to suggest that you smoke or vape anything in your situation, however I will tell you I love my electronic cigarette and after smoking for 15 years and now being smoke free for 2 years this is my experience.
First of all, you dont need to invest a ton of money, the one I use is low cost and it does the job, check it out:
buy electronic cigarettes When I started vaping instead of smoking the first thing I noticed was that in just a week, I did not have chest pain any more, I didn't cough or have difficulty breathing when I woke up each day. I did not have tons of flem throughout the day. And honestly it tastes much better. I have converted my parents and my best friend to e-cigs and they are loving it too. I suppose I could quit anytime I wanted to at this point, but I really don't see the point personally, I enjoy vaping and it does not make me feel awful like tobacco cigarettes did. I am playing ball again and loving life.
I really hope you beat cancer, Look into lowering your PH level a bunch of alternative healthcare advisors swear by it.
All The Best.!