First Love trauma, how to build relationship with someone who has it?

[twentytwo]

hey. iv been seeing this guy, we have this weird relationship.

two years ago he had a really painfully break up from his first love who was cheating on him, the relationship meant everything in the world to him, he was really sincere, but the girl dumped him in a worst way possible.

from what i see he has the first love trauma and now acts it out on other girls, devaluating any kind of romantic relationship and commitment but desperately seeking for one.

 

this is not the first time i'v seen situation like this. it seems like for guys their first love experience seems to determine all future relationship patterns, especially if the girl he loved cheated on him or treated him really bad.

 

i care for this guy very much but i know that it makes no sense being companioned and "sacrifice" myself for him treating him with understanding and stuff like that when he just acts out his bad relationship patterns and experiences on me. Now i have a question, how do you psychologically help out a person overcome such trauma? How can you break the patterns without being all cheesy and "understandind", "unconditionaly loving" and coping with all the bad stuff he acts out and how he behaves? there must be some research, books on this topic? i mean the first love trauma lets say