I seperated from my husband when our son was a little over a year. He's 3 now and the divorce is still not final. I had to take a class by a child psychologist about how children handle divorce. When he addresses children under 3 he said that they may become clingy and need a lot more reassurance. They tend to internalize all their feelings and wonder how it is going to impact them. Their main fear (usually) is "Daddy left me so mommy might leave me too" Just reassure your child that mommy and daddy both love him but they think it is best for them to live apart now, so they can be the best mommy and daddy to him. Lots of extra attention and love will help. Be prepeared that there may be a period of anger and agression by your little one. My son did a lot of biting around that time and some major tantrums. I hope things go well for all of you.
