1200 —-> 850 slide....when will I level out?

You will level out when you stop losing more than 1/2 of your games

The key is your Glicko number. It's a fairly complicated formula but basically the higher the number, the less certain they are about your current rating. I recently started out as well and at first I'd win a game and jump 100+ then lose and tumble back down again. The more games you play, the more "certain" the calculation is and the rating changes get smaller, your rating will also eventually settle around a number that changes less. I'm two months in mainly playing daily and even if I beat a 1200 player with my 1000 rating I only get like, +15.

Yes. You will have started with a provisional rating. Looks like you started with 1200. Then the system adjusts your rating based on the difference between you and your opponents rating and how confident it is that it has correctly estimated your rating which is the Glicko. As you win more games your rating will increase, and it will decrease if you lose more. It is roughly unchanged if you win/lose in equal measures. As the adjustment is based on differences, expect a larger change if you win/lose against someone rated significantly higher or lower than yourself.

Hi! My name is Lauren Goodkind and I’m a chess coach based and chess book author based in California. 

It seems like you still have a provisional rating.  No worries. I wouldn't worry about your rating.  Just play your best and have FUN!  

I have tips to help you improve your chess skills so you can win more games.  

I recommend playing with a slow time control, such as game in 30 minutes.  You need time to think.  Beginners tend to make a lot of silly moves with very little time.  This makes sense since there’s a lot of pieces on the board.  
 

I also offer a  free beginner’s free eBook on my website, www.ChessByLauren.com in case you are interested. The book is about asking questions before each move.  
   Before each move, I highly encourage you ask questions before every move such as, “If I move here, is it safe?”, “Can I safely capture a piece?”, and more.  

Also consider all checks and captures on your side and also your opponent’s side. 

Learn basic tactics such as the fork, discovered attack, pin, and more.  I offer interactive puzzles on my website: https://www.chessbylauren.com/two-choice-puzzles.php  
If you are serious about chess, I highly recommend you hiring a chess coach to help you.  
I hope that this helps.