If you really love someone, I don't think, or at least I would hope, it never stops. It may change and you may go different ways but I can't see all of it ending. (Never having been in a relationship that ended, I'd have to defer to those who have gone through it though.)
JD, you're back!
I wish I knew the answer to that and why years of a relationship has to end just because someone decides they don't feel that anymore.
Love doesn't stop. Life just moves on.
Loving is something that the lover does. When the feeling goes away, some people think that it is OK to stop loving. Well, to "love" or not to "love" is a choice you make. How you feel usually will wax and wane.