How does married life change after having a baby? Would like to be mentally prepared for this and not taken by surprise!

Before the baby came along, my hubby and I led our lives outside separately and came home to each other. Currently with the baby, we are always on Whatsapp discussing abt what our baby is doing (I'm a sahm) and interesting places we can bring her. Our lives, decision-making and everything else revolves around her. We spend less time with each other as a couple. Dates need to be planned now; no longer soontaneous, less supper, no midnight movies. We also snap at each other a lot more but reconcile after few mins. It will take more effort to keep the marriage going. :)