Crank but no start

Hi all. I have a 98 legacy outback 2.5 that doesn't
want to start. There is a high pitched crank. I have
replaced the battery, ignition coil pack, spark plugs
and wires, tested the starter,  and changed the fuel
filter thus far. There was fuel in my old fuel filter
when I removed it so I don't think it's the fuel pump
but I'm not sure if that's any indication. Fuses all
seem fine, water pump, tensioner, timing belt and
thermostat we're all replaced a few months ago.
The car has always run a little rough but was
always pretty reliable. I drove to work one day and
when I went to go home it just wouldn't start. After
replacing the plug wires it started and ran from my
work back to my home and the next morning would
not start again. I'm thinking it may be a sensor or
maybe a loose connection somewhere? I'm
running out of ideas and money, HELP!