1997 Jeep Grand Cherokee no heat

Hello, I have a heating problem it runs around 200 on the temp gauge but blows cold air. I noticed that when starting to come up to temp it bubbles back thru the over flow tank and once the t stat opens it stops. The top and bottom rad. Hoses are hot but still blows cold it has never overheated as to say lost antifreeze all over the place. Once it is at temp and I shut it off the is a slight drip in the front of the engine behind the fan once in a while. Thanks for the help.