Little advice please :)

[a153fish]

I would say it's probably in breeding mode, but don't let your guard down, as sometimes the snake is really sick, and waiting to find out later just adds to the situation. Is there any females around him, that he may be smelling? Also try feeding him a small meal, like a fuzzy, just to kick start his appetite, and also to see if maybe he regurges. If he does regurge then you know it's something that needs to be looked at. I am just thinking if there is no females around him, he should be eating. But then it could be instinctual, and like a built in clock.