You may have a hereditary tendency towards arthritis, but that does NOT mean you are doomed!
Not only did he make a tasteless attempt at a joke, but any doctor who says nothing can be done when he hasn't even tried anything isn't worth his license.
Go see a rheumatologist.
Meanwhile, much of the pain from arthritis is due to joint inflammation. Besides anti-inflammatory medications, you can structure your diet to minimize inflammation-causing foods.
One folk cure that has been known to help is apple cider vinegar. Bragg's really does seem to be more effective than, say, Heinz. You put a tablespoonful in enough warm-hot water to make 1 cup and drink it down. Do this 2 - 4 times a day, and you should feel an improvement in a few days. Keep taking it, and you'll feel better as time goes on.
Once you get some of the pain gone, you need to exercise to build up the surrounding muscles. I'm not saying strenuous exercise, but stretches to keep your range of motion, weightlifting (you can use soup cans if you don't want to use dumbbells) to build the muscles, and walking as you're able. Strong muscles will support the joints, which will make them less painful.