I'm tired of my service going out.

If you really unplugged everything for 2 hours, 5 times a day, that wouldn't leave much time for actually using the service.  It's time to try something different.  If you've replaced all the boxes several times, you probably have a signal issue.  If you schedule a tech to check your signal, Cox will charge for the service call if the issue is on your side of the demarcation point.  But, if the issue is on Cox's side, there's no charge.  Either way, you'll probably continue to have the same issues until you identify the cause and have it fixed.