I feel your pain. Our family contracted this when my children were in elementary school and I was in my 40s. A friend who also had this at the same time ended up in the hospital being tested for lupus.
We all had terrible joint pain - the knees were the worst for most of us. I am sorry to report that over ten years later, I still have random join pain (not really chronic) that I attribute to B19.
I notice that when I first get out in the sun (playing tennis) each spring, I get a mild rash on my legs, concentrated around my knees, that looks the same as when I had the initial disease.
The intermittent pain doesn't really impact my activities; I am probably more physically active than my peers.
I don't know if it will help in an acute phase, but taking 2 tablespoons of flax oil daily helps me more than anything with the chronic joint pain and general aches.