I think it will work super well.

First he might think it is only to get him confused… yes this person is attempting to fool me … saying that she loves me and that she has to leave me now as if the 2 things made sense together …

She ’s a liar, confused but confusing, she doesn’t know right from left, up from down, bottom from top, but from and …

​well think about it for a minute

I love you but i have to leave you now.

First you present proposition 1 – i love you – as valid. And more than its validity, what is fascinating really is the world this first proposition drags you into … composed and organized by its own specific rules, emotions, feelings, behaviours, expectations, etc.
then you say but
in order to afterwards introduce proposition 2
as also valid, with its own world, its peculiar existence etc.
all this in apparent contradiction to proposition 1.

And the but is really here to say that both propositions are valid in(one)same world.
And you yourself are quite puzzled by the existence of this world where those two facts which you honestly take for being utterly contradictory are both true, and even more, are both true simultaneously.

Often you even wish you could say them at once. It would prevent you from leaping into conventional confusion …
So, what interests us really is the relation between the 2 propositions …
It seems one would annihilate the other, and yet it does not.
It seems there is a problem, a lack of logic somewhere, something that defies reason, that you have no other choice butand to admit … so you say but.

You could have said and.
Try it again.

All animals are equal and some animals are more equal than others.

I am only one, and still I am one. I cannot do everything, and still I can do something; and because I cannot do everything, I will not refuse to do something that I can do.

Not only is there no God, and try getting a plumber on weekends.

Trust, and verify.

Sometimes it gets quite interesting :
To be nobody and yourself in a world which is doing its best, night and day, […]

And we sometimes hit a problem :
God is not dead but alive and well and working on a much less ambitious project.
God is not dead and alive and well and working on a much less ambitious project.

After all, we will always find a need for a but.
Perhaps when the 2 proposition are essentially exclusive, essentially contradicting one another …
… love and hate, life and death, black and white … we all know it all … love but hate, life but death, black but white …
And in fact here but brings those words and concepts closer together … much closer than and could have ever done.
And keeps them apart – but asserts that they coexist, that they belong together.

But last and not least, you will also find in this world a need to replace and by but :

Liberty but Union, now but forever, one but inseparable.

Sex but drugs but rock but roll.