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.