God can make something good out of your mess! The test you’re experiencing will become your testimony.  2nd Corinthians 1:4-5 says, “God comes alongside us when we go through hard times, and before you know it, he brings us alongside someone who’s going through hard times so we can be there for that person, just as God was there for us.”
You didn’t sign up for this crash course in single parenting? No, God enrolled you. He’s taken the intended evil and rewoven it into this curriculum. Why?  So you can teach others what He’s taught you. Rather than say, “God, why?” ask “God, what?” What can I learn from this experience? Rather than ask God to change your circumstances, ask Him to use your circumstances to change you.
Life is a required course.  Might as well do your best to pass it!  You will get through this!