Re: Cold Sensei
I hadn't picked up from your earlier posts that you're now being excluded from 'dojo business' circles that other people of your rank and status are not being excluded from; I think that's a more troublesome aspect, if I'm now understanding you correctly. Do you think that your relationship with Sensei at this point is also damaging his ability to teach you and/or your ability to learn?
I can understand why you wouldn't feel comfortable directly approaching him at this point, but maybe you could ask another yudansha to speak with him on your behalf. The only other options that come to mind would be to accept relative stagnation where you are, or to move to another dojo.