[uoaei]

The point of nihilism is that there is no "should." There are no logical conclusions from nihilism except all of them. If you feel a connection to fellow sentient beings, act in accordance with that. If you see them as your tools, then act so.

This frees up your moralistic framework to be solely realized by your own ethics. It takes some time to clarify and arrive at them, sure, but it necessitates an active engagement with the world and your influences upon it.

Or not. You could just use it as an excuse to live in hedonism or to off yourself. But that choice is entirely yours and you take ownership of it whether you want to or not.