Know when to take extra projects and when to say no.
Do your job because you love it and show that, get the results, you will be able to say no.
When you say no explain why (perhaps getting more on your plate means other stuff needs to drop?).
Amazon can be a great place to work for or it can consume you quickly. You need to do what is best for you.
It was a great place for me for a long time, .oved to another company two years ago to reset my brain.
I would recommend anyone to get a job with Amazon just to see how Amazon approaches work. Caveat, I worked in the software development/quality jobs so I am talking from that perspective.
Continue looking around from time to time, worst case your Amazon experience will be a good sign on your resume.