Why is this happening to me - If I stay, can I ever trust you again??

The day we said i do was the happiest day of my life.
Knowing your mine and I'm yours.
Knowing I found the man my son love.
Knowing I don’t have to be scared any more.
Knowing I have at least one person that i can be me and don’t have to put a show on for.

The day we found out that I'm pregnant, i knew you'd be the greatest husband and father.
But not even 3 months after being married you started to show signs.

What did I do wrong??
Sorry I was looking out for our unborn child.
I'm sorry I wasn’t there to hold your hand everywhere you went
I'm sorry for everything thing that you see wrong in me.

The day I got the call that made it all real that you was seeing some other bitch.

I just want to die.
I couldn't breath.
I couldn't see strait.
I couldn't think right.

The man I said I do and love with all my heart.
The father of my unborn child
The man my son so much and cry each time he left
The man that promise he'll never cheat on me

Now what am I to do, you were my whole world.
How can I tell my son he won’t see you any more?
What do I tell your child why mommy and daddy isn’t together

You tell me that a part of me loves her like I love you.
God I just want to die and then I won’t have to tell the kids.
Oh and she might be pregnant with your baby but you still want to work it out.

Now you tell me she was a mistake.
You only love me and you want to stay a family.
The words I want to be true but is it true or a game?
Do you want to be with me for the kids or me?
What should I do, I’m so scared now.

Why is this happening to me??
What should I do??
Should I stay with the man I love so much or not???
If I stay, can I ever trust you again??