In general you should not have extensive scabbing after surgery. If your doctor is taking care of you and says this is normal, go back and ask your doctor to help you clean or wash it better.
Your post operative care is terrible as the crusts remain caked onto your head. Be sure not to pick these off as you now have to wait until they fall off with twice daily shampooing and leaving the shampoo on your head for 5-10 minutes and gently massaging the crusts until they fall off in the next few weeks. Your doctors should have told you how to wash your hair immediately after the surgery so you would have looked like the picture in the web reference below I can't imagine losing grafts with all of the caking on your head but as these cakes come off, if you don't follow the above advice, you could lose grafts