yes, that can be true but not your fault.  my wife was the same way, too tired, sick and even lonely to make love.  Its the BP and the meds doing it to her, not you.  They will lose their sex drive, blame others for it, and even express feelings like divorce, separation, and being isolated.  I understand and I feel for you.  Watch her very closely and be sure she takes her meds.  BP can be very severe.  keep your own mental health in check also.

this is my second reply to your problem, but i know how hard this can be.  My wife was the same way, then all of a sudden, she is mood for sex at midnight, after I am tired.  Bher BP1 is rreking havoc on our marraige.  Stay strong for her and for you.  Your spt is the strongest show of love, realize she cannot help this and be sure to keep your mental and physical health in check or else you're both be sick.  Pls stay away from having any affairs over this, that would be bad for her and you.  If I can help further, let me know.