I'm so sorry you are experiencing this. It is probably best, though, to let him pass naturally. If you do think you would like a spell though, it would be best to write your own one. Start by learning the basics, energy manipulation, visualisation, grounding, all that jazz. Then writ your own spell and cast it yourself. You have to truly believe it will work though, otherwise it won't work.
Good luck i hope it all works out well for you.