@zygomidus yellow stool might be from toxic bile dump and steatorrhea. I would suggest eating some meat with all fat-high meals, even with the lube formula. This is because protein signals proper bile/enzyme release. Meat proteins stimulate stomach acid, pancreatic enzymes (lipase), and bile flow better than fat alone.
Its very hard to do (yknow because of the preparation of raw hard cheese) but eating a lil bit of raw cheese 10-15 minutes before each meal might do wonders, if the problem is toxic bile dump.
After some time hopefully you are gonna be able to digest fat better and get more weight from the digested fats. I wouldnt worry much about muscles, some weight you gained is gonna go to muscles to obviously.