Actually your fourbet size is fine. Fourbets are one of those spots where you don't have to reraise a spot. $3 is probably more optimal but in pos what you did was fine.

Idk how else to play this. Again, I haven't played microstakes in awhile and i dont know how much people in general are threebetting. I know in the live games we play this is a snap call. Normally, you should never ever fold after fourbetting. Here I probably cry and call. Just be assured that getting it all in here isnt enough of a mistake to care that much.