2005 Chrysler Pacifica Overheated Troubleshooting

The Pacifica ran hot on me first time I used the ac
in spring, and I smelled a chemical smell. I filled it
up with water and drove home with ac off. My
husband topped it off with water and said it was
fine but I did not use the ac in fear it would
overheat again. It drove fine. We had a family
emergency and had to drive it out of state to
Georgia. It was hot and my husband began to use
the ac with no probs, but I found liquid in the
passenger floor board one day, and the ac stopped
working as well.  Weeks it ran fine and didn't run
hot. Last week it was raining and not even as hot
as it has been and it suddenly ran hot. Bubbles
were in the overflows, and it was steaming. The
car shut off and would not crank. He let it cool off,
filled it with water and it finally cranked, but was
steaming and had a bad smell, like gas but we had
to get it home. It now has steam coming out tail
pipe when cranked and under car. This family
emergency  drained every penny we have and
caused my husband to lose his job. We have 7
children and are not mechanically inclined but we
have to have a car. Therefore, we will be diligent on
following step by step instructions on finding out
what is wrong with our car and fixing it. Anyone
that could tell us how to troubleshoot the problem
would be awesome. Someone told my husband to
get blue devil head gasket repair, and I am leery
about shucking out 60 dollars we don't have to
temporarily fix a problem especially if we don't
know where the leak originates.