just vs. simply

[Violino]

Which one sounds better? Or it doesn't matter which one I use? Is there any difference between usage of "just" and "simply"?

For example:
Don't go. You don't have to love me, just/simply be.

Greetings:)

[Cerberus™]

I guess it depends on context. Your sentence is a bit poetical, that is, I am not entirely sure what it is supposed to lead to. I'd say either one could be used here. If you gave a more common kind of sentence, perhaps more could be said about it.