I'm the same as you. A series of 2-3 year gigs. Some I left because I was bored and not getting any new challenges. Some I was laid off from. Some I left because for some reason everything I enjoyed about the job fell apart. My favorite coworkers left, the executives clawed back all the nice perks, etc

I'm in this situation right now. Just passed the three year mark and the new executive team is starting a rodeo

I honestly feel very down on myself, as if I'm incapable of staying at a job more than 3 years. Like I'm making excuses for moving on, not reacting to a change in reality