u/spacecadont

I got this prickly pear about a year ago and it was immediately unhappy. I ignored it for a while until it started forming this white chalky coating that I assumed was some sort of fungus and I moved it outside. I was convinced it was dead but now it appears to be sprouting new growth! What should I do with this thing? Should I water it? Bring it inside? Wait until the new pads get big and replant? Please help! I live in AZ where it is ~110 degrees F every day and the sun is almost always out. I have very little experience with cacti.