I'm considerably overweight, too, so I know the wrist/hand/arm pain you're talking about. I also tried changing things with my handlebars, sitting up straighter and steering with just the tips of my fingers (my backside didn't like that one) and everything else I could think of.
I was miserable until a person at work suggested that I get a recumbent. Honestly, I resisted because I really like the bike I was riding (a first anniversary present from DH) and didn't feel another bike of any sort was in the budget.
Long story short, I did get a recumbent and fell in love. No wrist pain. None. I can feel my fingers no matter how far I ride. (YES!!!)
Look into them. There are some really nice bikes being made, and many are made to take us Athenas - and take us many distant places with a smile on our faces.
Good luck no matter what you decide on. And remember, life is too short to ride a bike that doesn't make you smile.
Give big space to the festive dog that make sport in the roadway. Avoid entanglement with your wheel spoke.
(Sign in Japan)
1978 Raleigh Gran Prix
2003 EZ Sport AX