Frustration has started - husband had radical surgery earlier this year and he's not able to do what he used to. What can I do to support him?

My husband had radical surgery in May to remove his rt kidney, bladder, prostate and surrounding lymph nodes. Due to suspect cells he's also had 4 cycles of chemotherapy.  

Frustration at not being able to to what he used to, general things in the garden or take the dog for a decent walk are now beginning to show.

He wants to return to work but his job entails alot of lifting so I'm not sure that is going to be possible. 

I'm running out of things to say other than it all takes time and he's been through a horrendous change. We're still not sure what happens next but I hope we can get back to a new normal soon