Help my husband is gay

I'm in so much shock... tonight my husband told me he's gay and he's leaving me for a man. We've been married for 10 years and have 3 kids together. I had no idea and I'm so shocked and devastated. There were no signs at all. What do I do? How do i tell our kids and family and friends? I'm heartbroken. Did I make him gay or was I just the cover up all along?!