is head gasket sealer good

What is your question?

there is a milky look to my oil.. I was told my head gasket is cracked. harder on gas, seems to have a hard time catching it`s speed, Iwas told to put head gasket sealer into it, and others say NO. another mechanic told me sealer is good for about 1 hours drive, then don`t bother fixing the car just burn it.

What makes this problem better or worse?

milky substance in oil, hard on gas, won`t catch speed

How long has your 2012 Chevrolet Sonic had this problem?

a few weeks