How to fight a mive guy?

Today this guy randomly put me in a chokehold which I couldn't escape from. I need to know how to fight him. He is GIANT and FAT, about 6'3 and 250 pounds of fat, while I'm short, 5'4 and somewhat muscular at 130 pounds with little fat. He doesn't seem to know how to fight, since all he could do was put me in a chokehold and push me around. How could I retaliate if he attacked me again?