I always think my game is flawed, because, well, it just is!
In SSNLHE, the authors mention that Sunny Mehta had a 40 BI downswing playing $200NL preparing for the writing of that book in the section on BRM, but achieved a solid winrate over several 100K hands. That had to take several 10K hands to recover from - their BRM recommendation is 100 BI's!!! - so a breakeven stretch over a substantial number of hands is to be expected.
I would get concerned if I had a 15-20K hand breakeven stretch and I didn't think I had a serious leak in my game - not panicky, but concerned. Getting a review from a respected peer/better player can go a long way toward reassuring you whether you have fundamental flaws/tilt that need work.
I had a pretty terrible June (and knew I had major leaks in my game), but I think I've identified enough of my major leaks to have a solid July, in large part from everyone's feedback/discussions in this forum (including from you, thanks for that incidentally).