Head halters aren't a good idea for a breed prone to CVI.
Also, you may want to talk to your trainer about correctly fitting that prong collar - it's far too loose, and the links are too large. (we often train with prong collars at the club I'm a member of, and we fit our students' dogs with smaller prongs, fitting snugly and high up on the neck.
When the prong links are too large and too loose, you have to use a lot more force when correcting the dog - which isn't fair to the dog and is fairly ineffectual.