Demotion

This might seem like an unusual question, but how do I get demotion shielding off my account? I did ranked for the first time this season, got placed silver 4 and quickly got demoted to silver 5 where I have been stuck with a 30% win rate for FIVE MONTHS! And I STILL have a demotion shield on my account. I'm losing 20-23 LP per loss and gaining 14-16 a win, I really just want to go to bronze where I actually belong and stop losing in silver 5. Anyone have any idea how long until this demotion shield goes away?