If it came on “suddenly” , I would think maybe I was a chicken, getting cold feet and if it came on suddenly after 3 years I am not sure I would blame the other person for being immature. They may be, 3 years is a long time many pretty mature people would have some difficulty. Maybe the person who has this sudden change thing happen is immature too. So that maybe is a good reason to take a step back and see what comes of it. Maybe you will do some soul searching that can’t happen without the separation and maybe the whole thing would be a relief , but you can’t know.

My friends (I am not too involved with my family) were pretty good judges of the women I dated. They liked my wife as an individual and for me right away.
They were right.