If you find yourself puzzling about how your partner can treat you that way, it is because you are trying to live in a love-based relationship, when in reality you are living in a control-based relationship. The mental abuser struggles with his own feelings of worthlessness and uses his relationship to create a feeling of personal power, at his partner's expense.
You feel as if you are constantly walking on eggshells. There is a real degree of fear in the relationship. You have come to dread his outbursts, the hurtful things that he will find to say to you. (Maybe the same anxiety and need to please spill over into your other relationships also.)
Fear is not part of a loving relationship, but it is a vital part of a mentally abusive relationship. It enables the abuser to maintain control over you.
You can heal. Mentally abusive relationships cause enormous emotional damage to the loving partner who tries, against all odds, to hold the relationship together and, ultimately, can't do it, because her partner is working against her.
Whether you are currently in a mentally abusive relationship, have left one recently, or years later are still struggling with the anxieties and low self-worth and lack of confidence caused by mental abuse, it is never too late to heal.