Need words of encouragement

I have to take my 3 month old to my cardiologist appt tomorrow and I am having anxiety about it. He hates the car seat, hates the carrier doesnt tolerate stroller if it's still. I am just nervous he will cry the whole time. No matter the comfort the outside world is scary to him and unknown and I just want him comfortable. Need some words of encouragement and solidarity because this can be fucking hard sometimes.

To note. I have no one who can watch him tomorrow my only option is to take him. And cant reschedule as I need cardiac clearance for another procedure ill have in a couple if weeks.