If I don't go insane this next week I just don't know

Last week we got one of the female kittens fixed.  All went well and by the next day all her siblings were back to normal with her.  She is more affectionate and loveable now.  Three sisters left to go.  Today one of the sisters went into heat.  Actually I think yesterday she went into heat.  Then today another one of her sisters went into heat.  HOWEVER...We found her mounting the other in heat.  Was looking up if female cats in heat mount other female cats.  Well upon researching more, then inspecting our cat more we just realized she is a he.  For 9 months now we've believe him to be a her.  She had a puff but nothing protruding the would make us think she's a male.  She has the features, body, and temperament of her sisters and not like her brother.   She is dainty and just looks like a female cat, goes to the bathrrom the same way her sisters do. So...all I can say is ohhhhhh noooooo.  These two have been trying to mate all afternoon.  I have been pulling them apart from each other and keeping guard.  Tonight the girls will sleep in one room and the boys in another and our poor other kitty we keep separate will have to stay in the third room.  DH will stay with our older cat and I will sleep with the boys.  Only once when I walked to the kitchen did I hear a blood curdling meow, so I think he was successful, but hopefully not enough so.  I call Monday FIRST thing the minute they open and get them in, but I'm telling you...trying to do this while working full time is going to drive me insane and I don't know how soon I can get them in.  Hopefully they can make an emergency and at least get the male fixed.  I guess if by some odd chance they are successful at mating I'm hoping that if we can get them in this week that there will be no chance for a pregancy to occur.  Keeping my fingers and toes crossed.

Just needed to vent.