car won't start

My car has been overheating. I replaced
the fans, radiator and thermostat and it still
overheats. Although, I quit driving it as
much, I still drove it to test it out each time
I'd replace something. My car shuts off
once it overheats. The other day it ran out
of gas as it was overheating and now I
can't get it started even though all the
lights and car radio work. Before I tow it to
the mechanic I want to know if it's worth
putting anymore money into it. It has about
190,000 miles