After three rounds of hydroliase my skin on my cheeks is very saggy.

Thank you for your question and I am sorry to hear of your filler related issues.  Hyaluronidase only dissolves the hyaluronic acid found within fillers and not that found in your natural skin tissues.  You may be suffering with continued swelling and irritation from all the rounds of injections and I would recommend allowing your skin to fully heal.   Once your skin has returned to its normal condition, see a board certified plastic surgeon for an in-person examination.  They can help discuss treatment options.  

Hyaluronidase has no impact on normal skin. The enzyme only targets and breaks down the HA fillers used and does not damage skin. I suggest you compare before and after photos and speak to a very well trained cosmetic physician. Fillers and skin tightening can be used to improve your aging.  Best, Dr. Emer.