Rough idle sluggish

My car has a rough idle and is sluggish will only run about 30 mph Big-O looked at it for about an hour and came back with blown head gasket. No oil in coolant, no water in oil, no apparent leaks, no loss of coolant or oil. I have done most of my own work my whole life some I am confident on most things related to me vehicles, but could use a push in the right direction my apologies to Big-O, but I am a little skeptical.