Its more about whats going on than how big the downswing is. In your case its sounds like you are being brutalised by varience so i wouldnt worry. Take a look at where most of your losses are comming from. Are you getting it allin behind too often aswell? Are you building big pots and then folding when you shouldnt be? Are you building big pots where you shouldnt be? If none of this applies then you probably are a winning play who is just running like shit.

Having said that, if your roll is starting to get shorter, or you are starting to lose confidence/tilt then I would consider moving down to regroup. If you are still playing well and you still have plenty of money behind then ride it out.