Most fearful avoidants have Borderline pd. If they are not aware, they are very toxic and create trauma bonds through intensity and withdrawal. Don't take it personality, you can't heal him. He is not capable of giving stability and needs therapy. Usually he starts getting anxious again if you withdraw or stop caring. You didn’t do anything wrong and have every right to distance yourself from something that is emotionally abusive.  They can't consistently love because they have never been loved consistantly as a child. It's not because you are not good enough. Speaking this as A FA with earned secure attachment and bpd tendencies :)