Got screwed...beyond annoyed

So, lets go back to mid June....house has been on the market for three weeks and no offers yet.  Realtor calls.  "I have great news for you.  We have an offer, very close to your asking price, no issues with him qualified for the mortgage and willing to rent back to you until your new house is done.  Oh, there's another offer coming tomorrow, but just not on paper yet today."  I'm thinking, this is too good to be true.  Of course we take the offer!
Lets fast forward a couple weeks.  Buyer wants all windows replaced, stovetop range replaced, furnace replaced, electrical service upgraded, shower tub surround replaced, attic fan replaced or a $5,000 credit at closing.  Nope, not happening.  Windows are fine, yeah they're not brand new but fine.  Stovetop is fine, not brand new, but fine.  Besides, you're getting every other appliance practically new for free from us, so stop complaining.  Electrical service isn't a code requirement, but may be for his insurance and mortgage.  Fine, we'll do it.  Attic fan, I can do that myself for $75.  Same with tub surround.  Furnace, yeah I'll give you that it's old and about to die.  I finished the attic fan replacement myself.  New furnace is in.  Electrical service upgraded to 100 amps.  All for $2,000.
Now, fast forward a bit more.  We're 4 weeks from closing.  Hmm, haven't heard a whisper about the renting back, for how long, for how much?  I call my realtor for those questions.  She comes back to me the next day "well, his lease is up September 1 and needs a place to live, not renting back." 
1. When was I going to be notified of this change?  Were they really waiting for me to ask?  Was he going to show up on closing day and be like "dude, why are you still in my house?"
2. Did he change this?  Or was it my moron realtor that screwed it all up?
So here I am 4 weeks from closing, haven't started packing because I thought I had another month and a half after that, no plans on where to live.  So, now I'm scrambling to pack up, rent a storage unit, make plans to move in with the in-laws, make sure the kids dont have to change schools for a few weeks, cancel all utilities, etc.  Oh the stress!  My realtor sucked from day one and this is the final straw.  I have a strong feeling the buyer back in June said he could probably negotiate with his landlord and we can stay here until October, and she probably never said a flipping word back to him and his realtor.  Who gets screwed in the end?  Oh yeah, that's me!
On the bright side, our lumber arrived yesterday and framing starts Tuesday!