Why am I still jealous?

It's been more than half a year.
I've confirmed, unconfirmed, and reconfirmed
That I don't like her like that anymore.

I know she made me happy,
But I don't think I ever liked her like that.
I'm straight.

I have no reason to be jealous
Anymore.
In fact,
I couldn't ask for a better relationship with her.
I love my friends.

I know for a fact
That I'm done with pinning over her.
I don't feel fuzzy around her anymore
I just feel happy.

I'm not over-thinking this.
If anything,
I'm under-thinking it.

I'm not jealous cause I want her love.
I'm jealous because I want to be
The best friend I can be.

Which means no one else should be a better one.