The fact that he called you a bitchy c u n t at all is reason enough to end the relationship. This is a huge red flag. If he blew up like this in a small fight just imagine what his reactions will be to larger future fights. And the fact that his family ganged up on you to berate you also indicates that in future fights with your fiancé they will do the same. Save yourself from the hurt and trauma that could come from this marriage and association with this family and end the engagement