A common way we sabotage our relationships is we project a past person's actions onto the person in front of us. E.g. if we had a controlling mother, we quickly look for signs that our partner is controlling. The other person is repeatedly scrutinised for something that may not be in their character at all.
When a caregiver or significant person hurts us, we become hyper-vigilant of signs that the same will occur again. The brain is pattern-forming, but the trouble is, with repeated trauma, it can become overactive in trying to find danger where there is none. Noticing potential dangers everywhere is great if you’re a caveman with hungry lions about, and less so if you’re a modern human in a safe environment trying to connect deeply with a loved one.
Become aware of the ways that others have hurt you the most and check in with yourself: are you overly suspicious that others will be this way even when they show you evidence that the opposite is the case? Do you play out patterns that harm your relationship such as closing down emotionally, quickly jumping to blame, developing extreme anxiety because you assume the worst case scenario? Is there a conversation to be had with that loved one to share your fears and explain your behaviour so that you can move past the fear and strengthen the relationship?