I have to agree with Mike. When I was a DM, I was 5' 8" and only 135 lbs. I never had a problem dealing with panicked divers without ever hurting any of them. I brought in quite a few over the years. I never had to hit any of them. Once I was treding water with no gear when a woman popped to the surface in full panic right in front of me. By the time I knew she was there, I was her floatation device with my head underwater and without a full breath. I could have panicked myself, but instead, my training and experience prevented panic. I did not fight her. I used her body as a ladder and climbed down. Once I was no longer helping to keep her higher out of the water, she let go. No panicked diver will follow you underwater. I came up behind her, grabbed her tank valve, took her to the back of the boat where I handed her to the Captain. The Captain pulled her on board. There was no need to hit her or cause her pain of any kind.
If you keep thinking and follow what you've learned, panicked divers are not all that difficult to handle.