Phil Burt's Bike Fit¹ is great read on the subject, with lots of in-depth advice and solutions. I suspect the vast majority of the readers are Sunday Morning Warriors, but it does cover more relaxed styles which are likely more applicable to you given your bike. From the book:
“Some cycling ailments are confined to the elite and some to recreational riders. It is unheard of for me to see [...] our national squads with numb or tingling hands. However, I have seen serious recreational cyclists with quite debilitating hand-nerve injuries referred to me by local doctors.”
A good chunk of the book deals with off-bike stretches and flexing to cut down on injuries too. I've found better off-bike care has helped me a lot, and I know a good number of cyclists who swear by their yoga sessions.
Hope your situation improves!
Edit to add: He also has a few videos on Youtube with advice on improving your fit for comfort and pain relief, which is a cheaper option than the book ;)
“Some cycling ailments are confined to the elite and some to recreational riders. It is unheard of for me to see [...] our national squads with numb or tingling hands. However, I have seen serious recreational cyclists with quite debilitating hand-nerve injuries referred to me by local doctors.”
A good chunk of the book deals with off-bike stretches and flexing to cut down on injuries too. I've found better off-bike care has helped me a lot, and I know a good number of cyclists who swear by their yoga sessions.
Hope your situation improves!
Edit to add: He also has a few videos on Youtube with advice on improving your fit for comfort and pain relief, which is a cheaper option than the book ;)
¹ https://www.amazon.co.uk/Bike-Fit-Optimise-Performance-Avoid...