2005 Chevrolet Equinox 125000 miles original owner car wont start? Any information on electrical problems or key problems or just strange issues that you fixed to get car stating normally again?

I replaced the alternator , starter and battery over about 4 month period, and
dealer replaced the AC compressor.  My vehicle sometimes starts
sometimes wont.  It gets worse and more difficult to start  over time.  Last
night my car shut down on a major hwy after all the lights in the dash went
flashing for abut 10 seconds.  Jumped car went 7.5 miles and same thing in
addition when i hit break dash and light went flashing at an extremely fast
rate there were noises that come from different speaker at different times  
etc. Had to get towed because had 2 small kids w/me and couldn't mess
around on the shoulder. In addition they replaced a few months ago the
ignition because I could pull key from ignition while driving.  This was a
manufacturer recall that was hard to find they did work at no cost to me.  
Something is draining battery or just shutting car off.  I see this problem
replicated all threw the internet but never any answer most post people went
as far as replacing PCM and the next day car wouldn't start. if anyone has
any information about this 2005 equniox starting issue help please