This happens to me frequently, especially if I spend a lot of time studying or doing tactics trainer. My rating in blitz dropped from 1750 to 1580 after doing tactics puzzles and studying from a book.I'm pretty sure this is normal, since your brain is processing the new informatiion. It helps to stop playing for about a week, and then gradually you will become better and eventually get a better rating than with what you started. 1-2 months seems like a little too much time though.
My blitz chess rating suddenly declined

Glad to hear this is normal... Was worried I regressed without reason. Will stop playing and take a week or 2 off as you've recommended. Thanks! Anyone else - I'd love to hear your experiences too.
EDIT: I looked at your rating graph DorkInDisguise ... I can see excactly what you mean - quite funny actually how it goes up & down all the time, and I also clearly see the gradual improvement over time.
It happens to me regularly, too.
I used to wonder why - I'm pretty sure now that it's a combo of:
- Changing playing circumstances, such as playing in a random place on a cell phone often or in between work downtime, vs playing in a fixed private place
- Lazy thinking habits. If you get into a 'play lazy' trend where you don't think much at all, even in blitz, your rating can drop -100 for quite awhile. Takes a bit to bust out of that rut.

1100's and 1300 and blitz have almost no difference i have noticed , and sometimes the 1200s play better than the 1300s its just a matter of the ratings fluctuating alot in fast time controls . once you get to 1400 and 1500 you notice a huge difference reason why i havent beaten many of them

In my opinion a lot of players on this site play much better than their rating suggests.
If you compare my highest rating to my current rating there is almost a 200 point difference. I find that taking time off definitely helps. I play better with more time per move. I stopped playing chess for almost 2 years and recently started playing again. I play blitz not to improve my rating but to test out new openings.
Blitz goes all the way up to 10 minutes by the way and starts at 3 minutes. I don't find the timing too fast at all after playing bullet chess for months.
Rating drops are normal. I went from 1352 to 900 something at my lowest point.
I also strongly suspect that for 5 min blitz here, 1300 rating 5 yes ago is now 1150.
Guys like chessnetwork were crazy 4000 rated then lol. Evan ju was the highest rated player at one point, now it's nakamura.
So don't get too depressed about ratings loss compared to years ago - its harder now for sure.
1150s here can be really dangerous as well in 5 min blitz . I'm 1400 now in blitz here but get me out of book lines andits a dead even game most of the time. My wins over them are easier now mainly because book openings give me better attacking positions. I actually find it easier to beat 1259s than 1150s since 1159s are out of book and tactical by move 4 whereas I can usually outbook a 1250 into better positions.

People are simply using engines. It is very easy in middle of the game to start engine and quickly for 30 seconds to create positions and see best suggestions and let engine play next 10 moves or so then they continue from there with much better position and with advantage. Engine needs 1sec to show you best move and just 2 sec to move etc...
Don't play longer time controls than 3 min here.
I've recently started playing chess more often than usual and I noticed that in the last 2 weeks my blitz chess rating has steadily declined from 1332 to 1197. This leaves it only slightly higher than my all-time lowest, which was 5 years ago. I often played 1350 players with confidence and success; now I lose to sub-1200 players.
Has this ever happened to anyone else and is there perhaps a simple explanation to it, such as "playing too much". I have been reading a lot of chess books lately and I think I'm perhaps trying to apply the material subconsciously, rather than reading the position.
I assume taking a 1-2 month break will probably do me good but I am keen to hear of anyone who had a similar experience and how you've overcome it. Any explanations of why this sometimes happen will also be appreciated - perhaps teachers see this often in students?
Thanks guys! - Looking forward to hearing back from you...