arthritis in my shoulder

My arthritis in my shoulder has really gotten bad, and I am having trouble stowing items in the bed of my pickup truck. Aside from purchasing a new vehicle, does anyone have any suggestions which will help me handle the heavy tailgate or place things into the bed of the truck without aggravating more shoulder pain and stiffness?

I hope you are feeling better by now.  Does your doctor prescribe treatment for the pain?   My husband had injections of cortisone when the pain became bad enough. Again, I hope you are feeling better by now.