I think the biggest problem is falling within the diet. If you're not accurate with your measurements, food choices and meal timing it can make all of the difference. And a few pieces of licorice may seem like it's not much but over time any little slip up in your diet can have negative effects on your result.
If you have a sweet tooth, I would HIGHLY recommend using MAG-10 as a protein source. You control the amount of flavoring that you add to your protein and it curbs any sweet cravings, especially the grape or orange flavors.
Hopefully the last treatment for your knee goes well. Once you are able to get back to regular leg training it will help but until then you can make plenty of improvements just by adjusting your diet accordingly. The more specific you are with your diet and training the faster results will come. If you've been doing the same thing for 4 months with no results then something isn't right and changes need to be made. Without seeing photos it's hard for me to make an accurate suggestion for diet and I don't want to give you general information that won't be beneficial for your goals.
If you don't feel comfortable writing all of your personal info/pics here, I do offer customized training/diets and if you're interested you can send me an email to email@example.com