@rowan 46 it appears the discomfort follows on from the shoulder injury. I'm in same boat with a perma crocked neck and I have had to ditch road bikes and adjust my position on the flat bar bikes to adopt a more sit up and beg position and stance YKWIM to allow for a different weight distribution through the contact points of bars and saddle and maybe take some of the pinch and pressure out of your shoulder area and not have the same impact on the nerves passing through there. Try to ride as loose and relaxed in that region as possible, lower flappier (again YKWIM) elbows a lighter grip on the bars etc.
Otherwise, bar ends to give you different hand options, well padded gloves, different grips can make a heck of a difference, some people swear by the ergon type to kind of plant your hands in your optimal position for you but I find them uncomfortable and like more freedom at the wrist (
@Fnaar) that I feel they afford me.
All; now 2; of my bikes have front suspension tho - not shock forks or much travel & more by chance than choice but TBH I think body position and bike set up helps me more.
Good luck finding what works best for you.