Just a quick question about that enclosure. It appears to me from those pictures to be tall rather than long so it has more height than floor space. If you wouldn't mind while you are posting new pictures of it, could you post the actual dimensions as well. Also what your current temps are both cool and warm side and ambient humidity.

This store you got this snake from, what info did they give you about it as far as age, whether it was captive born, it's feeding history, how long they'd had it and where they got it from. Remember this snake came out of a store environment which likely means it was either never handled much or handled incorrectly. It may also have been exposed to customers knocking on it's enclosure glass, making it nervous and stressed when approached.

More info on this snake, it's living arrangment and it's past will likely help us help you better.