Separation and divorce are radical life changing events for adults involved in the case. For the children whose parents decided to either get separated or divorced the new situation after separation or divorce will be very stressful and hurtful. End of your relationship does not mean end of your and your ex-partner or ex-spouse responsibility towards your children.
Options to be considered
The best way would be to have an amicable settlement concerning your parential responsibility. In addition, it would include other arrangements such as visitation right and regularly contact between your child and the ex-spouse or ex-partner staying apart. Finally, it can mention child support payments.
Workig out an agreement can be a not easy thing to do. It might be even quit stressful especially if there are still anger and bitterness between the ex-partners or ex-spouses. However difficult it might be to have to comunicate with your ex, remember that you both should focus the well-being of your children. They have the full right to see both of you and to grow-up with both of their parents.