I probably would of done the same thing my first time if my Hamlet hadn't been so big but when you took the mouse away so that it wouldn't suffer, you are actually making the snake suffer around 3x more than before. Snakes need TONS of energy to get a bit of a mouse into their mouths but the energy is then created again from the mouse after it's digested. When the snake used all that energy and then couldn't restore it, you wouldn't believe how stressed he is... he's probably suffering as much as the mouse did when he was getting eaten! Your little milk may never eat again since she won't have enough energy to grab the mouse with and might die sometime soon. Although you probably thought that you were helping, you won't but I know that if you knew about this earlier, then you wouldn't of done it. I wish you the best of luck with her and I hope that she eats again.