Why can't I keep a lid on it?

Why can i not keep a lid on it?
Why do i not have a leash to hold me back?
I just cannot leave anything,
Even when i see I’m losing you with every word that said,
Bit by every nano bit.
I’ve finally noticed my faults,
I’m not perfect,
No one is,
I do know when i speak without thinking, 
The hurt I cause,
I can’t believe is to you,
Cos you’ve bought me into the brightest light,
When im with you I can’t help but be continually blinking!
I’ve finally found a lady that is so pure,
Natural beautiful and so heavenly sweet.
For me,
You are the epitome of perfection,
So why can’t I just accept no?
Why does my mind play such foul games with me and not stop from desecrating and defecting the pure and beautiful roots that between us we’ve grown.
You are to last person i want to hurt,
So again,
Why can i not keep a lid on it,
And stop the wrong words leaking from my over thinking brain!