ADHD and aversion to therapy

Forum: Anger, Frustration & ADHD

I would like to know why people afflicted with ADHD are sometimes averse to therapy.   I am at my wits end with my fiance and would absolutely try a last ditch effort to save our relationship as we have been together 8 years and engaged for 3.   But he refuses to go to therapy as he says he has done  "many cognitive therapy sessions" in the past.  He lives in an unfinished house and quite possibly a hoarding situation as well and will not take my advice to seek new  help, possibly new techniques afforded to those that suffer with ADHD.  I know there are other factors involved(porn, very low self esteem, no friends, distant from family and a very bad former break up) that all have never been dealt with.  Is it too much for me to ask?  Is the reason for not wanting therapy is because they are so plagued by pain and disappointment that they cannot bear any more criticism(positive) or pain?   Am I at a total wishful thinking point and wasting my time to try and salvage this relationship?  Or should I cut my losses?  So very sad all this!!