Fluctuations during your "Off days" and "on days" are quite normal. Might I ask what kinds of time controls you play these games at? The shorter they are (bullet, < 3-0 blitz) the more likely that your non-chess faculties can really fail you ... such as alertness, amount of distraction when you play, fatigue and mouse-slipping.
Another thing that can explain this behavior is that you are having technical difficulties closing out won games, i.e. you may be winning but not cleaning up the game correctly ... this ability (called technique) gets better as you get stronger, but it is normal to see players at your rating level "allow" their opponents to sneak back into the game.
As far as figuring out what to do about this ... try "increasing" the time between games ... and do something that's still chess-y and productive...such as
- Going over your game (on your own, with a computer) and looking at the mistakes.
- Going over deviations in the opening with a book/database, so that you're better prepared to handle the same opening "one ply" better the next time you encounter this line.
- Practicing a ton of tactics
- Going over annotated games, chess videos or just following/stalking strong players on the servers...you'd be surprised how much you can sponge by just observing their games.
When I feel like I'm on a losing streak, I space out the time between games a heckuva lot ... like 1 5-min blitz game, then atleast 30 minutes of a chess video or reading a book, before I start my next blitz game. This helps get rid of the slump and softens the ratings drop you are seeing. Rushing into another game with emotion/anger or trying to beat up on weaker players to regain lost rating points is ALWAYS a bad idea, especially if you're on a slump :)
My play goes thru a cylce that never, ever fails.
I get on a good run where the game makes total sense and I am giving players 200 points ahead of me fits and smashing those of my own ranking. I work my way up 100 or more rating points and then IT happens:
I free fall about another 100 points and cant even beat those that are 100 points below me. Its like I forget how to play. Im guessing and hoping im making the right move instead of knowing I am. It pisses me off to no end.
The next stage is usually a slow and steady climb over a long period of time where I regain what I have lost.
I dont want to get caught up in the ratings aspect of it here but it is a good reflection of how sometimes I think Im awesome and my potential is limitless and then with the flip of a switch im the absolute worst.
Do most players go thru these growing pains? Do you eventually maintain the state of mind when you are at your best or is it a constant struggle?
I dont think I would mind if I gained 20 points a month steadily but its the 100 point swings that aggravate me. I was a 1425 after 10 str8 dominating wins and then I went for 10 str8 losses and im back to 1330ish.