Worried? I don't think so. Worry is rarely constructive or therapeutic.

Prudently concerned and vigilant? Definitely.

The keys are to follow the directions/rules conscientiously, jump through the proverbial hoops, and keep a frank, honest and open dialog/relationship with your doctors - everything above board. Keeping a pain journal may help. Then if (<-- BIG "if" ) you get into trouble down the road, they'll be there for you and help you through it. It's doctors who feel they've been deceived/betrayed who wind up bailing on a patient or cutting them off.

There are always new developments and hope, but realistically, you may be on some sort of narcotic pain medication for the rest of your life. You're on a journey - it's a process. Keep reading, learning, communicating - about your conditions, your meds, chronic/intractable pain, and the politics that are increasingly governing its treatment. Become aware, pro-active, and your own advocate. All of these can help you keep on the path, and....

Reduce the Sense of Suffering, and
Improve the Quality of Life

IMO, your attitude and goals are excellent (but again, realistically, your dosage will probably go up over the long term; every patient/medication is different).

Doc