Lots of good advice here. My parents were divorced due to infidelity, so that made it worse. They were also not great at soft skills so it was fairly rough.
My friend group has had a number of divorces which we got to witness. The worst ones are where one party feels they were wronged. They were not able to get past that for the sake of the kids. They ended up out of the group and lost all respect of the friend group.
Is this good for the kid or not good for the kid is the only question you need to ask when making a decision.
You don't have to like your ex but must be able to communicate and make decisions with them for the rest of your life. Don't sweat the small stuff. Be mature. Is it better to argue via lawyers or take your kid to Disneyland? That is what it will cost, at least. Don't be petty. Do what you would want them to do. Listen to your kid.
Not to sound like a broken record on here but get therapy. You have not been divorced before. You don't know how it will go. Talk to someone that has seen it hundreds of times and can help you through it. Maybe joint-custody sessions as well. Try to get on the same page with your ex.
Finally, in the spirit of the poster, all in good fun... you need this shirt: