Please Help! New BP Owner!

[Daybreaker]

Ok, so I bought a 15-16 inch, pastel ball python July 6th. I've fed her 3 times so far. She has never turned down food until now. She has been VERY active since I got her and tolerates being held a few minutes at a time. But the past 2-3 days, she has just sat curled up in a ball for the most part. I have a heating pad on one side, humidity gauges, thermometers, and etc. I can't find any reason for her to be stressed, but she is very unactive and won't eat. It is around the time she is supposed to shed, but her eyes aren't milky blue and her scales aren't flaky or anything. Why is she acting this way? I'm super worried! She won't stay in the warm half of the 45 gal. tank either. I checked to make sure it wasn't too hot and the humidity was ok. She just wants to stay where it is cool, I guess. But now she won't let me hold her. She's being very irritable. Please help me!

By The Way:
I checked her underbelly and it looks perfectly normal. No rotten scales or anything. Why could she be acting this way?

I didn't discount their advice. It just didn't answer what I wanted to know.

Hiding is a good thing, as a "hiding bp is a happy bp". She may be hiding more so right now because she may be going into shed (you might have missed the blue stage or it's on it's way): I know my snakes become hermits when they start to go into shed and will remain that way until they're done shedding and ready to eat.

She may be angry/defensive if there's something off with husbandry (which others have already given very good suggestions on).