Have to stop for a few days, nervous what will happen!

I have to stop breastfeeding for 48-72 hours next weekend because I need to have an MRI done with contrast that is dangerous for baby. I have Multiple  Sclerosis so the exam and contrast are absolutely necessary but I'm afraid this is going to put an end to my breastfeeding. I'm pumping as much as I can but unfortunately being a teacher I don't get much opportunity to pump at work and will not have a large enough supply to sustain for days so I will have to supplement with formula. Will the formula make him not want breastmilk anymore? Is it going to be hard to get him to latch again afterwards? He takes a bottle while I'm at work but I'm not ready to be completely done with him breastfeeding! Please ladies any advice or experience you can share with a situation like this is greatly appreciated! In freaking out over here 😫