in order of editing:
(1) you have offset bushings and undesirable camber a clear option is to replace bushings to centric ones... no?
(2) offset bushings are offset precisely for the reason of affecting the camber. if you have them and the camber is undesirable then they are not put on right. they must be turned to set the desired camber. this is the obvious and clear straight forward option.
(3) mind you that turning the offset bushing besides affecting camber also affects toe. So the trailing arm must have two offset bushings since there are two dimensions for manipulation. And the distance from the front wheel has to be retained - this also is affected, a third incidental factor. This is not an easy task and can very quickly swell your head and frustrate. The easiest option is to simply replace the bushings to regular centric type, it will provide at least an improvement...