Winning/losing streaks: my form makes no sense to me!

Hi! Brand new to the forum, been playing on the site since about September. Mostly 10 min 'Rapid' games. I've played more than 1000 games now, so one might assume my rating is pretty accurate (if pretty low by the standards of many on this site!) so my runs of form don't make sense to me. I fluctuate wildly between runs of wins, getting to a rating of upwards of 900/950, followed by runs of losses, heading back down below 800. Currently, I think I'm down at 761, having been rated 980 not long ago. More than a 20% fluctuation! I know I often make blunders but, if the ratings are accurate, then surely a player shouldn't have such difficulty (barring the odd anomaly/stupid mistake) beating most players rated 20% lower than them? Wouldn't they be making blunders too? (And probably more of them?) Imagine a 2000 rated player losing repeatedly to 1600 rated ones. It most likely wouldn't happen. Can anyone explain what's going on? (For reference: I also play a computer chess game, which has me rated at around 1400. Similarly, I play the computer engine on here at that level too. Obviously they're not 'Rapid' chess games, but these runs of form still feel weird to me.)

One thing I can suggest, what helped me personally is make sure you develop all your pieces and connect your rooks. You will end up having much better games and play more consistently that way. 

I have this too. Kind of like a panda,Ic you get comfortable and relax. Then serious and focused, and it oscillates.