Raven, welcome to the forum! Actually, this site is for people with any type of liver disease.
Your doctor has probably already told you that the main treatment is weight loss. Close control of your sugar levels is also crucial. NASH can possibly lead to cirrhosis, over time. Basically, NASH is not as serious as other liver diseases, so there is no need to panic.
I will say that diet is probably just as important for you as for me with hep C. Try to avoid red meat, as the liver has a difficult time processing it, and increase your fresh or frozen vegetable intake. Since fruit contains fructose, your intake of that would depend on your sugar levels. I can't recall if we have any other members with NASH, but if they see this I'm sure they will have something to add.
For the curious, this is a great link to a picture of the liver, gallbladder, and biliary system:
Raven, more likely your constipation is related to the Oxycontin you are taking. Calcium can also be constipating.
Have you tried increasing your water and fiber intake? Hopefully, you will get some of your questions answered when you see your doctor. Write them down, so you won't forget!