Hate to say it Glen but it sounds like this eyepiece has a fault , looks like something has moved inside throwing off the optical axis ?
Where did you get this one , local ? and if so take it back , most retailers will do a replacement without any fuss .
But I have never heard of an eyepiece being Ok and then suddenly having major 'Coma' all of a sudden
, that's what it sounds like from your description .
Good luck .
Brian.