"A lot of it is also mindset to help you deal with this. When I got to the point where I wasn't able to do certain things it got somewhat depressing. I tried focusing on what I could do and tried to find new things to do in place of what I wasn't able to do.
What worked for me may not work for someone else. I always felt worse when I moved less than when I moved more. There is a lot out there that can help those of us with arthritis. There is not one magic thing. We each need to figure out what works for us."
This. Quoting my Cathlete friend from her above post, this is what I would tell you. I got diagnosed with arthritis in my hands and fingers 2 years ago and depression was the immediate response. However, after I got over the denial period --extensive, I can tell you!-- I got bust researching, reaching out to fellow Catheletes,a s you are doing here, and trial and error experimentation.
Movement is better than non-movement. Maintaining mobility is vital as we age, even through arthritis. I have it in one of my toes joints also now, so I cannot powerwalk 4 days a week anymore, but I can still manage 2 if I want, so, I'm good with that. I have good weight lifting gloves to help with holding weights in my hands, can;t do it bare palmed anymore. I am learning to loosen my grip to help prevent excessive swelling of fingers post-exercise. I take supplements and ibuprofen when inflammation hits. I keep moving, at least 4 days of intense exercise out of every 7, but I move a lot all day too.
Just as with any injury, take another look at your exercise DVD collection and also, other instructors and DVDs out there and see what you can still do and what you can't anymore. Don't hold onto DVDs filled exclusively now with moves that cause you excessive pain. Sell them on and get them out of your collection so they can no longer cause you sadness.
Katie Daniels, fellow Cathlete, is an inspiration. I don;t know her forums name, but I follow her as a Cathlete on FB. She recently suffered a massive physical trauma that has forced her to change completely the way she exercises. She has not given up, she has rallied. She now posts her daily workouts and they feature all her PT exercises and also Suzanne Bowen's BareAmped routines. Bowen's routines are very arthritis-friendly. Check them out. As we age and we encounter physical limitations that ageing presents to us, we may have to countenance methods of exercising that we never would have accepted ding in our 20s and 30s. For me, and I suspect for Katie, barre/pilates work such as the BareAmped series is a case in point. However, these will promote health and fitness and help maintain our sanity through pour need to move every day. So, don';t feel alone in this: we are all being challenged by the ageing process --arthritis is a backhanded gift of that process!-- and all revising our exercise routines.
Keep doing what you can without horrendous pain, and keep moving. Cathe's LIS series, barre and pilates workouts, swimming and walking were made for this period of our lives.
Clare
..I can't go all the way down using dixie cups..my knees sometimes hurt too but I've always had bad knees..sometimes my knee cap feels like there's fluid inside when I do to much..I still workout 6 days a week..I'm sometimes wondering if I should only do 5 days...it's so depressing; (..thank you for listening 
