Can I change the oil & add engine restorer w/out having to replace head gasket?

What is your question?

1994 Ford Escort Wagon. Just fixed the water pump, timing and oil change a few weeks ago. Just recently had to replace the water outlet gasket and the freeze plug because the coolant/water was leaking all out. I drove at least 10 miles and it ran pretty good. Right after that, it ran hot, coolant started bubbling from the coolant reservoir tank and the car had shut down. Now, there's water mixed with the oil and white smoke coming out the tailpipe. The car still starts. I wanted to know, do I need to replace the head gasket? Can I change the oil and filter and add engine restorer to the engine without having to replace the head gasket?

What makes this problem better or worse?

White smoke coming out the tailpipe and water mixed in with the oil in the engine.

How long has your 1994 Ford Escort had this problem?

A week.