It's important to take the time to be in the moment, all that hard work and effort for the future is creating great things around you and you should stop to enjoy them...it doesn't mean your forward progress will be halted, in fact you'll probably find it accelerates.

but I'm doing what I can and hopefully I'll eventually leave this planet in a slightly better shape than I found it.

You can't ask more of yourself and that's a lot more than so many are doing. Be content, happy with it, work for the future, yours and the planets, but don't forget to be present in the moment, right now...It's all you have.

I've definitely never thought that I'm living my best life

Nope, maybe not...but you're living your life meaning what you have is it...so be present. You deserve that.