I Have Been Under Treatement For A Sinus Infection Which

I have been under treatement for a Sinus infection which a operation helped dramatically. The cough still did not go away so I was put on really strong anti-biotics and have taken them for about 3 weeks. I also do a irrigation with the irrigation stuff and also irrigate with a anti biotic have to extract from a bottle with a suringe. My oxygen level is 91 and I have 0 energy contrary to my normal self. I am 74 two years ago I went thru 6 bypass open heart surgery. I did not awaken for 5 days. This surgery was brought on by my constant cough, only the sinus surgery and drugs fixted that. I keep going because I basically have to for $. What should I do to help? I also do a inhaler and nose sprak 2-3 times a day