This is your craigslist Boa? I think now you know why you should buy from a reputable seller.

Also, you dont have any of the appropriate equipment before you bought the snake???? Excuse me for chastising you, but this is exactly what I and many others were telling you to take care of first, prioritize.

Call a vet asap and get him checked out, not even debatable at this point. You took him on, take care of him no matter the cost.