It looks like th horse is in a left lead canter in those photos. You look a bit twisted in the saddel, with your upper body facing leftward some , leaning forward and your left shoulder drawn back.
you also have a kind of "thrust" into your stirrup which is mostly likely the product of a locked knee. It means your leg cannot drape down the horse, and this makes it harder for you to follow the canter motion. You look to be too rolled forward on your pubic bone, too.
More relaxation all around will help. but then, that's hard to do when you dont' ride a lot. I hope that is helpful and that you can get more riding in. The horse is lovely .