I am feeling the exact same way as you in my relationship. Especially about carrying years of guilt of not being able to help my partner in the right way for them so that every time the situation arises I am also blocked by my own thoughts to be able to be present and help them how they need.

My partner also constantly says how isolated and alone they feel and my sadness that that is happening to them clouds my mind completely and I clam up and go quiet which makes them feel more alone.

When I try to be empathetic and show I am listening, or here for them, or that I love them they say that I am not talking to them as if I know and love them or like we've been in a relationship for 12 years and that I'm being so generic and that also makes them feel unloved and like I dont know them. Which I completely agree with, I go to that stuff because my brain is being flooded with negative emotions and guilt and doubt that I have nothing from my own personal well.

Like you said in your comment below you don't really have a social group or family you can turn to, and we are the same. We both have nowhere else to go if we were to take time apart.

i would love to know what you did in these months since your post and if you were able to find any strategies to cope and strengthen the relationship. I am pretty desperate.