Strange Room Setup a Rubik's Cube?

I think my problem may be different from what most people encounter as one tries to confirm that the speakers are in the perfect spot.. I am trying to get my speakers set but having a problem as I read all the suggestions about standard formulas. You see the house was built in 1841. the floors are heart pine, with a wool rug and the ceilings are 11 ft plus. Let me get to it.. The gear is set up in the living room which is almost square 17 long and 19 wide..ouch. At the back of the room behind the listening position are two giant doors that open ( 7 ft wide x 10 ft tall) to the dining room the exact same size as the living room.. I keep these doors open, in effect, making the listening room larger, right?

So I am sitting almost in the middle of these 2 rooms. In trying to use the Cardas formula and others I am not sure what dimensions to use. I do not want to go broke on room treatment without having a good idea about speaker placement and listening position. Now the speakers are about 7 ft from the rear wall and 6 ft from the side wall in the living room.
My chair is on the equi-distance triangle between the speakers. I just plotted the graph for this setup and it was ok except for a big bump at 50 hz. The speakers are spiked and I have a few sound traps that don't seem very effective yet. Jennifer Warnes Way Down Deep is boom city.
So getting a little frustrated and looking for some ideas for a DIY fix since I cannot afford Rives.