Heyo,
Lately ive been having some troubles. I usually just become lucid by just somehow knowing that I am dreaming and the reality check comes after that. Lately however as soon as i realize Im dreaming i start falling all over the place uncontrollably. I dont understand why because I used to be way better at controlling my Lucid dreams. Just lately however its been impossible. …and they have been really short. Whats happening?
A couple of random ideas from a newbie 
How experienced in LD are you? If you are very experienced and have no problem controlling LD’s and whatnot (or if you have high-lucidity ones more often than not), then perhaps its like that control is manifesting on its own in the form of chaos and confusion before you confirm it to be an LD.
Or maybe youre really anticipating LD confirmation and all the stuff you can do, so you get really excited and whatnot and start to lose control or perception/concentration…this may be irrelevant, but is it sometimes like you cant wait to finish the RC so you can get on with the dream? Then again, if you already know its a dream why do you do RC’s (im guessing to ‘confirm’ it more and increase your consciousness). Maybe it could be something to do with the RC’s you do? Try any new methods lately? Anything in your life change perhaps?
Or maybe your subconscious is trying to trip you up for some reason 
what do you mean “falling all over the place” ??? does a hole open up beneath you and you just start falling through it ???
anyway, i wouldn’t worry too much about it, my experience with lucid dreamings is an up and down, you may just be in an ebb right now, you’ll come out of it better than before
and maybe you can turn your falling into flight if you don’t wake up too soon that is
good luck 
thanx