For years now I find myself discontent. I thought it was my need for advancement, so I have kept trying to find better jobs and moving to fill them. Now I'm starting to think it is me and not the job. Anyone else going through this?

In a world where we are pushed to think about "What's next" to make us happy, it is not uncommon to feel the way you are feeling now. Whenever this happened to me, I knew it was a sign to recenter myself and be in the present as opposed to constantly thinking about the past or the future.It's probably worth doing an audit on your 1) career, 2) personal life and 3) everything in between. 1) Career: what excites you in your day-to-day? And what have been some common themes that have given you joy and excitement in your past 3-5 jobs (depending where you are in your career, can be less if you're more junior) 2) Personal: what makes you the happiest in your life as a whole and how can you maximise it so it become more at the center 3) everything in between: what are the relationships you want to maintain in your life (not just romantic, but also friends and family... family members aren't always the sanest people to be around, it's a hard truth), what do you want to prioritise in your everyday routine (e.g exercising/movement, spending 30 minutes on your own doing whatever, something else) Good luck, you got this!!
Agree with Iynna, definitely time to take stock of definitions of happy, successful, etc. I’ve been here before, where if I’m not driving to the next challenge, I’m bored and unhappy. Lots of self reflection to understand why (still working on this lol) and to really find happiness in the ‘now’.
Sorry to hear you’re in a bit of a funk. I might suggest taking a sabbatical to do something adventurous that’s not work related. Do something you’ve put off doing and step out of your comfort zone. Go on an adventure someplace or try a new activity. Years ago, I felt burned out and underwhelmed by my life. I somehow decided to go hike across Spain by myself and it sparked something in me that changed my world. I discovered that there was more to life than my job. Not to say this is what everyone needs, but maybe if you can even just try out a new activity in your town - you might rediscover parts of yourself you’ve kept hidden. Feeling discontent is very normal, and it comes in and goes like waves. Wishing you the best.