Gather as much email/calendar event records, phone records, meeting records that showed you had to work overtime hours at night and weekends regularly and save all that information into a USB drive....If you get a shitty severance, it might be work talking to these guys and sue qualcomm
http://www.lieffcabraser.com/Case-Center/IT-Overtime-Pay-Law-Tech-Workers-Overtime-Rights-Explained.shtml
You got nothing to lose at this point, and everything to gain