Is the phrase 'keep your act together' ever used?

Question

At the beginning of the movie Klaus, the narrator, Jasper, says:

Letters. You don't really write many these days, do you? But I bet there's one you never forget. Send it off to a certain plump guy in a red suit and, provided you’ve kept your act together more or less, he’ll drop off a toy or two. And yet, no one seems to wonder how the whole thing got started in the first place. This is a story about letters, and it began with this one.

When I googled to learn more about the phrase, I couldn't find anything. I got results like 'get your act together' or 'keep it together'. I think that 'keep it together' has the meaning that was intended by the phrase 'provided you've kept your act together' in the movie. So I am wondering if the phrase 'keep your act together' can ever be used.

Answer 1

As you've found, "get your act together" is the usual present-tense/imperative version.

However, once you have got your act together, you need to keep it in that state. To use "kept your act together" implies that not only have you got your act together, you have been able to maintain it.

He needs to get his act together. (Present/future)
She certainly got her act together. (Simple past: one-time action)
You have kept your act together. (Done it and maintained it)

The "act" in "got/kept your act together" is not the same as "it" in "get it together". "Get/Keep it together" is [I would say] more to do with emotional well-being — or at least, not breaking down — whereas the "act" is the whole shebang: emotional stability, being law-abiding, even not having your mother clean your room.

Urban Dictionary can be useful for slang, but it's user-maintained, so sifting the wheat from the chaff can be necessary:

Get your act together: Get situated , get your life in order