Hello. Thank you for your new question and thank you for requesting me. I apologize for the brief delay, as I was not at the computer when you submitted your question.

Divorce dissolves a marriage. Custody does not, unless it's handled in divorce. However, custody matters can be addressed even if no divorce is taking place. If no divorce is taking place, a parent can petition to establish a custody order without dissolving the marriage. They're really two different issues but custody is necessarily handled in divorce matters because the issue cannot really be avoided.
If a custody order has been issued previously, the court may evaluate the issue again during divorce, though it may decline to if the order is recent. If the custody matter is pending, it will generally be handled as part of the divorce.
You definitely want to retain an attorney to protect your interests. He or she may suggest that you seek Temporary Custody to protect your rights regarding time with the child. However, custody isn't handled on a "first to file" basis and, instead, regardless of who files first, the court should look at the custody matter based on what's good for the child. There should generally be no legal advantage to filing early or filing first, though it can be wise to seek a custody order early to establish one's access rights to a child because, until such an order is established, both parents are legally equals.

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