What country are you in? England? There has to be some way to get an MRI and see someone who can fix shoulder problems. Start making some noise.
I'm an orthopedic surgeon and fix rotator cuff problems routinely as part of my practice. But.......
It's pretty hard to recommend a fix before getting the diagnosis correct. Who knows what's really going on in your shoulder? Maybe it's not even a cuff problem. Ultrasound can be useful, but MRI will show the fine details of the soft tissues beautifully, allow you to see if there is a tear, partial tear, or just tendonitis. You can also see the cartilage, ligaments, other tendons, bone spurs, and other details that an ultrasound will often miss.
Age is only one factor that determines if a person is likely to be successful with surgery. Some surgeons might disagree, but the tear type and size, tobacco use, other damage in the shoulder, and presence or absence of diabetes are all more important than age. I've refused to operate on tears in certain people in their 40s and I've had success operating on some tears in people over 80.
And, for all you Americans...... I live in a rinky-dink part of the USA Rocky Mountains and there are at least 6 MRI machines within an hour drive. One of them will do walk-up studies the same day or the next day for cash. Any of them can get you in within a week. At the private centers a simple non-contrast shoulder MRI is a few hundred bucks, including the radiology read. It's at least double that at a hospital. Sure, we have some healthcare problems here (mostly from government and insurance companies), but at least help is available. Most of the world (even the developed parts of the world) has to do without or wait forever to be seen.
