Just a little story -- When my youngest was 6 months old, my XH took off with a bar fly and never looked back. It was the beginning of Winter, the economy was in a recession, I didn't have a job and 4 kids to feed. FOCUS ON YOUR BABY. That got me through. I got a job, and the rest just worked itself out.
Plus, focusing on the kids doesn't give you as much time to worry about MLC'r. They need you, he needs a therapist.