I've had metal put in my elbow and ankle due to serious breaks and the only thing that helped was getting it taken out... if that is at all a viable option for you, I recommend it. I've talked to older people who kept their metal in and they say it just got more stiff and painful with age.
I'm keeping my ankle plate in because there would be a long recovery time (some non- weight bearing) but in the future if it gives me significant grief, I will have it out. I did get the 2 syndosmosis screws out (those went from one side of my ankle to the other) and having those out increased my flexibility and decreased pain.
I got the plate taken out of my elbow this past January after it had been in for 2 years. It was right under the skin, it sucked. I hit it on stuff all the time and it fucking hurt and I tried to strengthen my arm to get it back its pre-surgical state, but exercises made it hurt like hell and my elbow would be stiff afterwards. Getting the metal out instantly gave me range of motion and cut down on the stiffness and pain.
The less metal is in us, the better off we are. I'm really sorry, the collarbone sounds like a horrible spot for injury and metal... best of luck