It is like a door that won’t open until you have tried it many many times. I first thought this about grief. You can try to overcome it and not succeed, and this is a part of grieving.
I have also confronted the door at the end of a love-affair. I seemed to disconnect from the world outside. My memory began to go, and feeling withdrew from my head and hands and skin, and settled in an unexpected sob in my chest. There were no paths leading from the centre. And sometimes the thought in my chest would become very sore. Once I found myself walking down the street carrying a shopping bag and crying quite loudly.
After each outburst I thought the worst was over, the knot of emotion had dissolved, I could pass through the door and close it quietly behind me. My concentration returned, and I looked out. But the door was still there. The knot moved up to my throat and my anger spat “you bastard, you bastard!”
I am still not through the door, but now I do not stand close or turn its handle. I expect one day I shall open it easily as I walk past on my way to somewhere else…