Hi Irene,
If I recall correctly you ride an Easy Motion Street with upright riding position and front suspension. You wouldn't get any benefit from carbon handlebars on that bike. Oftentimes discomfort or pain can be attributed to two issues, first is not enough time in the saddle and second is a death grip on the bars.
Time in the saddle can take care of itself, I know for myself after just two days off the bike, I feel different than if I ride everyday or every other day. When I used to take the deep winter months off the bike, that first week riding in the spring was brutal. Your body needs time to acclimate to this new pursuit and it never hurts to do stretching exercises prior to and between riding.
The death grip is done by many cyclists and motorcycle riders and takes a conscious effort to relax while riding. Oftentimes I hook my thumbs on the grips and rest my fingers on the brake levers in an effort to relax my hands. Wrists, arms and shoulders can be a little more difficult with upper body weight resting on them, it takes greater core (stomach muscle) strength to minimize stress to those areas. Again exercise and time in the saddle will help.
