http://www.hbvadvocate.org/hepatitis/Basics/HBV%20Basics%20PAP.pdf
hope this can help too
i saw a post time ago about a compassonate supply of entecavir by their website directly
http://www.baraclude.com/
https://www.pparx.org/
if it still too expensive go for generic tenofovir which is more potent and cheaper, about 98usd per month.
if you happen to have friends in poor asian countries like vietnam and others brand viread from gilead is sold at 7usd per month there