Inevitably, when entering into a relationship with somebody else, we soon discover the scars, wounds and sore points of the other. This often happens unconsciously and we might say "oh, she's really sensitive in this matter" or "he always overreacts when we talk about that topic".
We might handle this lightly, roll our eyes and sure enough we'll soon press this button again - deliberately ("oh, she really must get over this, it's so childish") or "by accident" ("oh dear, I forgot, this is part of his "neurosis").
Often, we don't even realise what's at the bottom of our partner's sudden outburst, tears, anger or other strong emotional reaction - we think it's because of xyz issue (not washing the dishes, flirting, going out with mates too often...). Whereas, in reality those buttons relate to fear of abandonment, rejection, intimacy or being unlovable - part of our individual life story.
Lucy Beresford writes that
at the moment of button-pressing, each person sees The Other as a monster who must be defended against. The Other is seen as selfish, hateful, abusive or deliberately cruel.
And therefore we think it's our partner who needs to change for things to work out for us. She continues that we realise that The Other is not a "fused version of us", it's painful then to realise that we will never be able to control the other to become something he/she is not.
For me a very helpful thing is to first notice all those hateful thoughts in my head (such as "oh, she is so mean, she doesn't love me, she wants to hurt me, that beast!). Next look at those statements and ask yourself "are they really true?"; "Do I REALLY believe these thoughts?", or "why would she/he be with me, if they were true?"
This usually helps to calm those thoughts down. By relaxing yourself, notice how your heart beat slows down and hey, suddenly you can even think clearly. It might help to go out of the situation at this point (if you happen to have these thoughts while arguing). Now it's time to reflect. Because, I am sure you know this already: it's only yourself who can change! (Seriously, it's no point waiting a lifetime for someone to finally change! I mean, they might, but only on their own account, not because you ask them to).
So, ask yourself what makes you think those thoughts? What buttons were pressed? What were you afraid of when you came up with these thoughts? Why did what your partner said or did made you feel so strongly? Can you relate it to something that happened to you in the past? Past hurting?
Are there any unmet needs you carried into adulthood from your childhood? Crucial needs like unconditional love, attention, freedom, compassion or respect?
Once you are able to see where your emotional reaction is coming from, you can then formulate what it is you need, communicate that need (and your fears related to not getting it met). It might be that your partner is able (and willing) to be more mindful of this need of yours or that you are able to get it met by somebody else close to you.
However, you will be able to realise that when those painful reactions come up ("oh, I am so horrible, no wonder she hates me") you can trace this thought back to your unmet needs, rather than think about your partner and why she/he has said/done something and how she/he must change. Then you can react by opening up, talking about those innermost feelings and fears - and believe it or not, it will make you connect deeper, rather than disconnect further.
The most helpful idea here is that what comes from YOU is about YOU!