Be happy you got it at 46, I've been dealing with it since I was 26. There's a few various ways to combat it though.
Do your bindings have canting? With stance alignment this is a huge thing most people need between 1.5 and 2.5 degrees of canting, but can go as extreme as 3 depending on how their stance is to ankle/leg alignment. You have to see if you pronate or supinate.
The other thing is arch support in your boots. The key to this is to have a footbed that also corrects ankle/leg pronation/supination as well as supporting all the arches in the foot.
Supplements are key as well. I have taken Glucosamine Chondroitin with MSM and Hylaunic acid on and off for the last 5 years. It comes down to sustaining and building up the Sinovial fluids in the knee to keep it lubricated.
Keeping your weight down as well as stretching regularly will help. A brace becomes a crutch that causes other muscles to over compensate for it. I blew my MCL and Meniscus up a couple years ago and wore a brace for one year only to make it through the season then strength trained for 8 months to build up all the muscles around it to hold them together.
Talk with the doc see what they recommend, they more than likely won't recommend homeopathic supplements as it seems to go against what they're taught.