I think it sounds great. I'm so proud of you too. You're totally saving the planet :)
Seriously, good balance of why you're qualified, what you want from them, etc. Are there names you should drop about specific people you want to work with and why their research is up your alley or anything?
ETA: I re-read and might change this sentence:
I decided to spend
some time in the work force. I wanted to make sure I could
wholeheartedly commit to being a graduate student before applying.
Maybe you could say something about wanting to narrow your focus with real-world experience. This sounds like you questioned your commitment (which may be true, but might not be something you want to share :)