Respectfully request advice as newly divorced dad

I'm so sorry to hear about your situation. I've was there years ago with my three children. We can all give you advice on FABO, but it really doesn't mean anything until you speak to an attorney with a good reputation. Laws vary from state to state. Only a local attorney will know the nuances of your area.
Divorce sucks .....for children and most often for the father. I suppose that some couples get through the experience amicably, but I believe that is not the norm. I hope that Texas courts are fairer than Lancaster, PA courts are towards the father. Remember that child custody situations can change over time. I started with shared custody but eventually ended up with sole custody of my children. it's best to dig in and prepare for a possible long-term battle.