I agree, stop with the mineral oil. It is very common for this to happen when mineral oil is used. Also, no more soaking. It is unnecessary and it does not help with shedding. It is stressful for ball pythons. If he feels he needs to soak, he will do it himself in his water dish. You do not mention what his temps and humidity is at. Also, what do you feed him? Rats, mice? Frozen, live? Have you switched him to a new type of food lately? Since he has stopped eating, have you tried something new? Males reach sexual maturity before they are year old up until a year old so he has past that point I am sure. Also, do you feed him in his enclosure or in a separate feeding tub?