Nicole, keep the necklace, it is sentimental and it was a gift.
As far as the comment our b/f or ex b/f made about you being like your mom.....hmmmmm.... could it possible be true? Is it true? Have you considered it?
I do not know you and I do not know if the statement is true. You may totally know that you are nothing like your mom.
I do not know why this comment was made to you????? sometimes it is best to listen and consider statements like that. You may discover he was right...you may discover he was wrong. If he was wrong then maybe the break up was a good idea. If it was right maybe you have things to work on. Maybe you could admit these faults if they are true in anyway and talk to him about getting back together and work on those problems. Good Luck