You are a good mom, Marina. Your love for and focus on your kids is wonderful.
Remember that all they need is one parent to be solid. You can be the rock for your kids, your constancy toward them, even your son who is suffering the most, can bring them through this difficult time and help them understand that there is always someone who loves them as they should be loved. My son has suffered so much with my H's crisis but I have to believe God has a plan for them, as long as we keep giving all the love we can, no matter what happens.
I believe I will see the bounty of the Lord in the land of the living. Wait for the Lord with courage. Be stouthearted, and wait for the Lord.