Even on your worst days at your current job, hopefully you understand how lucky you are. Have you ever had a crappy job? Maybe it was in high school or right out of college. Have you ever hated you job, where just the thought of going made you want to curl up in a ball and not move for the rest of the day?
Think back to those days and then reflect on how far you’ve come. You will still experience rough patches, times where you’re working through a difficult project or working long hours, but it could be worse. It could always be worse.
Remember that whatever stage you’re in, this too shall pass. If you’re upset about how something is going, do something to improve your situation so it passes quickly.