I don't think the Mane N Tail conditioner is bad. At the moment, it may seem like it because you are suffering from protein overload. Just keep doing moisture treatments and try to get your protein and moisture balance together. It's not exactly the conditioner's fault, you could've used any other conditioner with protein that much as the main way to condition hair, and you probably have the same effect. So, try to use it when needed and switch from moisturizing to protein conditioners depending on what your hair needs.