You need a good lawyer. We can give you support, but in this situation you need a good lawyer, so you should spend time and energy interviewing lawyers. Since your wife's responsibility ended at birth of son, I assume that she won't ask for that many hours with him. Since what happened, happened, you might be entitled to ask that her time with son be supervised (by relatives your trust, for free, or by state-registered and state-licensed professionals, for pay, possibly split between the parents 50'/50).