Help! My system is very bright it hurts my ear

Many times tube systems invert the signal. Try swapping the speaker hook up by changing the positive to negative on both speakers to correct the polarity to an even number. See if that helps the sound.

I would highly suggest you replace that high end cable you probably paid to much for and replace it with Canare.  It has the ability to leave the detail and remove a considerable amount of brightness.  One system has Mogami, and my old Swans M1 (HiVi F5 with Planar Tweeter) speakers loves it, but my new DIY speakers (HiVi F5, with a Fountek ribbon seem way too bright with the Mogami (one of the truest interconnect cable you can buy).  I moved it to my other system with Canare, and the brightness disappeared but the detail did not.  In the past, I just bought good cable and didn't think about the affect, but now I pay close attention to what I use.

Audiolad, I agree that Canare makes excellent cables, and use it myself (StarQuad). But I think that it's too neutral for the OP - what is it, about 200 pF per metre? I think that the OP needs more than that, like a box store interconnect, and a selected (but still cheap) speaker wire.

Room treatments are a big plus but just in case no one has made this suggestion,  adjust the crossover frequency and LFE in puts through your pre amp. Personally I'm a tweaker running the same audio / video file until I get it right. You may find that helpful. 

Unfortunately, most of the advice you've received is idiotic. You need to start with the basics. Show us the frequency response of your system!!! Get a CD that has a pink noise track on it. (i.e. Stereophile test CD). Got an iPhone? Get the app called "analyzer" for $14 bucks. Then show us what your system response looks like at the listening position in response  to pink noise. It's just stupid to recommend a solution to your problem without making the correct diagnosis. A frequency response is the first place to start.