Hey there and welcome to Living With PsA! That is an impressive acumen for a swimming coach you’ve got there! Fortunately for you, swimming is considered to be one of the best exercises for those with arthritis, so its awesome that you have been doing it for so long. Apart from that, another great remedy than exercise is some much needed peer-to-peer support and our community is a great place to find that. I encourage you to start getting involved in discussions - and the PDF file in the “Guide” tab provide some useful beginner tips.
Have a swell time and holler if you have any questions!