Do i have a bad head gasket

Hello
I have a 1997 mercury Sable (v6) so about 2 weeks
ago when I started the car it would idle but it would
die out so I was driving to work and the car just died
out I was able to get it into a parking lot and I noticed
that steam was coming from where I put coolant so I
drove it to work and after about 2 hours I checked the
coolant and it took all I had and it didn't even top it of
so I took it to a shop and they did a diagnostic test
and two separate carbon test and both was positive
indicating head gasket failure and suspect leak is
internal they put on seal tabs to reduce coolant so I
had a friend of the family to look at it he works in a
mechanic shop plus going to school to be a mechanic
he said he 98% sure it's not a head gasket and told me
that it's either a hose or the water pump or the
radiator can someone help me out thanks