[seszett]

That doesn't really have the same meaning, and sounds very awkward though, especially because "saluer" needs an object.

I'd say (considering the context, the meaning is that she "told me goodbye" too many times before): Elle m'a trop dit au revoir.

That's 6 syllables (7 if you pronounce the schwa) and I think that's close enough to what Maroon 5 mean in their song.

Elle m'a trop quitté could work as well, with 5 syllables. I don't think you can get shorter than that, each word here seems necessary and as small as can be, to me.

If you can spare a few syllables, "déjà trop" or "trop souvent" would make these sentences much more natural.