Welcome to the Healing Well Wrapped Club! Glad to hear your surgery went well and your home and recovering. If you can walk, it'll help your shoulder pain. I found the more I walked, the better my shoulder felt.
It's very normal not to have a BM at this point. You aren't eating much, which slows things down, and you're on narcotic pain meds--another constipation culprit. When your pain subsides enough to make the switch to liquid Tylenol, it'll help. You'll probably be able to make the switch during the day before making it at night when pains seem to be magnified.
The "phlegmy" issue might even be caused by esophageal irritation. I remember about Day 4 I was creating so much mucous/saliva I had to keep spitting it out. I do understand the pain of coughing...I had a lung infection during my recovery and coughed constantly. If you're coughing and creating incision pain, try ice. It worked great for me.