I am sure you do this already but need to take a washcloth and gently clean the eyelids to remove all the debris.
Also, are you using nighttime eye ointment ? Your eyes are sticking together because of dryness. Do you have a humidifier in your bedroom. I have a small one that sits on bedside table. I know this may sound strange but opthalmologist suggested this year's ago...do you have any swim goggles? If you can sleep with them, keeps so much moisture in the eye...like a moisture chamber.
As for opening the tear duct surgery, I cant provide any advice. I have one tear duct which was sealed a long time ago to see if this offered any improvement to my dry eye symptoms. I chose not to go ahead and have any other tear ducts sealed off. In the last two years, I have had side effects from the sealed duct! And my new opthalmologist (other retired) sent me to an eye surgeon to see about opening the duct. By the time of my appt the problem resolved on its own so the surgeon felt no need at this time (that was a year ago). Your situation sounds different than mine.
Again, the eye will dry out at night. Important to use drops, nightime ointment, swim goggles or safety goggles and humidifier. If you wake up in the middle of the night, put drops in. (I am a poor sleeper, so whenever I awaken, I put drops in).
Best of luck to you in solving your eye problem.