(Advice Needed) Help with Keeping my Little Friend Alive

Hi! I need some advice keeping these azaleas alive. Last spring my family uprooted a large azalea bush in our yard. I thought it was a waste but it wasn’t my decision. But when we were throwing it out this little clipping fell off and i decided to plant it in a spare pot we have. I’ve never done gardening before but i threw some plant food in before replanting it and hoped for the best. It immediately lost all its flowers which made me think it was done for, but it didn’t die and started slowly growing. I kept it near the fence in my yard because i was told they like partial shade. I kept watering it and cleaning out the pot (which i think might be too big) over the course of the summer.

I live in a place with cold winters and as the fall set in the leaves started to lose color. And now with the temperatures really cratering i got worried and brought the pot inside. I don’t know what type of azaleas they are, if they are supposed to lose their leaves or if theres anything i can be doing to help their chances. But i’d like to keep this guy alive if i can. Any advice for keeping potted plants healthy over the colder months? Should i have left it outside? I thought about buying a lamp for it but wanted to consult knowledgeable people first. Any advice is greatly appreciated!

Pic 1: now Pic 2: 1 month after planting