I have a problem with my left trapezius. i haven't been able to lift weights for fear of hurting it more. what exercises can i do?

Exercises: It's unusual to have an isolated trapezius problem. My advice would be to do exercises that do not aggravate the pain and try to gradually add in exercises in a few weeks that we're hurting that area, but start with very low weight.

No heavy shrugs: Light upright rows and lateral shoulder raises can help work this area without taxing it too much.