I am so sorry. You know I went through all of this with Filou who also lost that much of weight. In the last months he could eat whatever he wanted and he ate an unhealthy diet of goose lard ( very little), egg yolk and fresh chicken fillet ( I always cut it up in small portions like 50 g and froze it)- but all those things he ate with appetite.
I send all my best thoughts to you and Yodee.