HELP!!!

Awhile back I posted about my engine missing and running hot(2.6i) Someone gave me some info that it could be a cracked head and that these heads are famous for cracking. I did pull my head and found it to be warped really bad. So I sent it to the machine shop and they told me it wasn't cracked but yes it was badly warped. The machine shop did shave it. I put it back together and problem is now worse. My colant overflow always gets sucked up and lots of air bubbles from the radiator when I rev the engine. Someone suggested that the head is cracked and the exhaust is going into the coolant. I'm about to give up! Can anyone give me some advise???