I believe the answer is: Trust versus mistrust; isolation
trust versus mistrust happens since early interraction between the child and the caregiver. not resolving trust versus mistrust makes edwin tend to hard to put his trust on people that has similar characteristics with the caregiver that let him down .
This would eventually lead to the feeling of isolation since every individuals crave a certain level of intimacy and yet Edwin cannot trust a person enough to be intimate, which trap him in a vicious cycle.