Your message struck a personal chord with me because my best guy friend is an ENFJ and behaved similarly to what you are describing (though ENFJs and the relationships with them all vary). After a pretty serious problem in the friendship arose, he shut down. He only spoke to me in short, matter-of-fact sentences, that indicated he was upset with me but then when I asked about it (several times), he would not acknowledge that he was upset or mad at me. When I’d ask to hang out, there would be excuses when before there were none and when we did eventually hang out, it seemed like he just agreed so I wouldn’t get mad at him for not being available. In person, his entire demeanor changed. No jokes, no positivity; only a cynical anger at the entire world and despondent eyes. I couldn’t take it. I had tried to get him to open up but after being met repeatedly with a brick wall, I decided the only thing I could do was to give him space. I would contact him every once and a while and if I was met with the wall again, I’d give him more space. Eventually, after a few months of giving him space, I contacted him again and his dark cloud had lifted. He’s still not 100% the way he was but I can be his friend again and that’s all I wanted. The rest is up to him. I know now that I can’t be responsible for his happiness.
This story may or may not bring you any comfort because I know that not contacting a significant other for months isn’t the same as not contacting a friend. You can’t give a partner space like you can a friend and still have them be there for you. And I also can’t guarantee that this will help. I didn’t know if the right thing to do was to give him space. All I can say was that in my case it did help. Still, my advice would be to take a break, as difficult as that is, because you’ve done everything else there is to do. Kindly tell him everything that you feel needs to be said for his sake and yours and then give him space. This may work, or it may not. We don’t know because it is entirely up to him. If he comes back to you then great, but if he doesn’t, know that you did everything you could.
People have to learn to take responsibility of their own emotions in relationships, not just the emotions they can evoke in their partners. If you’re feeling down, that is going to upset your partner-not just you-because you are a unit. Which is all the more reason to place a lot of importance on self-care. Being good to yourself truly is being good to your partner as well. If you love your partner and want to do right by them, you have to love yourself first.
I think INFJs and ENFJs need to take heed of this lesson especially. Being the extroverted feeling NFs, our strong idealistic feelings have a tendency to focus too much on making the other person happy over ourselves which can cause major problems if we ignore things that we need as well. And even though INFJs like to think of themselves as the biggest martyrs with the scariest dark sides when pushed too far or asked to give too much, nothing scares me more than the Mr. Hyde side of an ENFJ.
On that lovely note, best of wishes my dear, and I hope your Mr. Hyde turns back into Dr. Jekyll soon but if not, know that every failed relationship is just practice for the next, and possibly final, one.