Gryff wrote:
I haven't played online for a couple of months and before each game would either earn or lose you 10 points, but now when I play each game is worth over 100 points and the people I play are of similar rating, why is that?
Your RD increases if you don't play games. If you haven't played for long enough, that can change a lot and your rating changes will be larger until you get more games completed after you return.
Read the section on Glicko RD
https://en.wikipedia.org/wiki/Glicko_rating_system