can't help but
To be forced to; can only; must.
When the streets are full of melting snow, you can't help but get your shoes wet.
When a friend gave Jim a ticket to the game, he couldn't help but go.
help oneself
To take what you want; take rather than ask or wail to be given.
Help yourself to another piece of pie.
John helped himself to some candy without asking.
help out
To be helpful or useful; help sometimes or somewhat.
Mr. Smith helps out with the milking on the farm.
Tom helps out in the store after school.
To help (someone) especially in a time of need; aid; assist.
Jane is helping out Mother by minding the baby.
When John couldn't add the numbers, the teacher helped him out.
so help me
I promise; I swear; may I be punished if I lie.
I've told you the truth, so help me.
So help me, there was nothing else I could do.