If it hasn't been so long, but you are reluctant to confess something like me, "I lost patience and screamed at the kids AGAIN", read this article.
Go anyway, you need the grace of the sacrament to keep fighting the good fight.
Firm purpose of ammendment doesn't mean overcoming sins as a Lone Ranger, toughing it out alone before you are worthy to come back to confession.
It's more like a little child, with a hurt finger which he got while touching the hot stove Daddy had just warned him about, running to him for comfort in his pain nonetheless. Does Daddy refuse to pick him up, and, shaking a long finger at him say, "I told you so!" No, he scoops up the little one, kisses the burnt finger, and then says it. With tears in his eyes at the hurt he sees.
Come home to the sacraments for Christmas. You can give no greater gift to yourself, your family, and your God.
HT Danielle Bean