Replaced the Alternator it drained my battery, It started having a parasitic draw. I replaced battery because it was over the warranty. The first day with new battery was fine. Then I left it parked for a few hours and it will crank but will not stay running unless I pump the gas and hold the pedal. It's sluggish and after running for 15-20 minutes it starts right up.
From your description of your problems, it points to a continuing problem with a parasitic drain. Whilst not an every day event, sometimes a new alternator can be defective. Your alternator may have been damaged in transit or may not be an incorrect replacement for your vehicle. The electrical system needs to be checked out again, and a scan for any contributing faults from elsewhere other than the alternator and battery.