1. Baby sleep is not intuitive at all. Learn as much as you can before the baby comes. Read "Precious Little Sleep" by Alexis Dubief. Figure out how to get a baby to sleep without them being on you, even if you are patting and shushing them in your bed. Having a baby fall asleep on you constantly may cause massive problems after the first 4 months. You don't need to use "cry it out" if you get the basics of baby sleep right early.
2. Pick a reasonable amount of time (e.g. 6 months, 1 year) and say the baby and your family are a priority. For this period don't get too caught up in when life/work/friends/hobbies, etc will get back on track. Just say "I said X time, and right now baby and spouse are the priority."
3. Remember to forgive yourself and your spouse for the fights, bickering, and mistakes. At some point you will take a week to figure out something and feel you should have figured it out in a day. You will feel like a failure. Then something else will change and another week will go by and you will feel like a failure again. Just take a deep breath and keep trying. Kids don't come with a manual.
4. Some kids are easier. Some are harder. If you are doing your best, that's all you can do.