I'm sure that overbet river always means nuts on microstakes. Therefore you should fold.

Your villian didn't think about your range , he just had nuts and he made overbet.

Naturally someone says "It's so nitty", but in my experience he always shows you 5x+

BTN is probably not too good given his stacksize.
Therefore i would proably c/r flop or c/r turn and try to get stacks in vs him.

As played its true that overbets from fish are generally strong from what ive seen, however in this case i cant really fold he might view AQ or KK,AA as nuts or have Q7 or whatever. He could also be bluffing ofc since your hand is verry underrepped.

Thank You guys! 

@BigFiszh: I can't like these comment because of an unknown reason...

I'd fold. Given that he bet small the two previous street and suddenly overbets, I think most of the time he has a monster. I do agree with Getready2rokk that we need to c/raise either OTF or OTT to get stacks in. However, once the huge river bet comes in, we're dead. 

(yes, raise the turn)  

i'm calling this river unless we know villain is passive.  villain can easily think a good queen is the best hand, and he can bluff b/c our range looks so weak ( tho i think he's rarely bluffing this way)