Since injuring by lower back at work, cantering has become a nightmare for me(and probably my poor horse

). It has gotten to the point that I realize I have been avoiding canter altogether as I feel it is stressing my horse out. For example when I ask for canter she pins her ears and swishes her tail angrily and rushes forward into a flat out trot and if I let her she will fall into a fast, unbalanced canter(as a reference her saddle is correct fit and back has been checked).
Have been practising transitions to avoid the rushing although I have been thinking it is more probably caused by a dread of my body being so uncooperative in canter(much to my disgust in myself :( )
CAn anyone offer suggestions/tips on working past the horrible bouncing.