How hard can sharing be?

My girlfreind has been living with me for a month now.
I just gave myself up, caught red handed.
She is living with me, not me living with her, even less us living together.
She is in my house, sleeping on my bed, eating off of my plates, using my towels...
How hard can sharing be?

Don't get me wrong, I absolutely love my girlfriend!
I have no objections of us being together under the same roof, au contraire.
I support it, desire it, enjoy it very much too!
So why can't I simply say "our" to everything?!
Believe me, I have to focus on these moments, cause "my" comes out very easily.

It's easy to refer to us when put in the future tense: Our kids, with our house, and our lives, etc.
Present tense, I struggle, and it hurts.
Simply because she doesn't share, she gives.
I receive...and keep receiving.
How hard can sharing be?

Of course she's investing.
I'm aware of that, as well as the common hope: To receive more than invested.
and as well as the common theory: The more you invest the more you retrieve.
She needs to start receiving or I 'll pay a steep price.

Truth be told, Of course I know the reason...

How hard can sharing be?
Less than living with fear.
And even lesser than living with regret.