Hi, I'd like to help you with your question.
From your description, it does sound like you are being abused. Abuse can be in any form. It is a myth that you have to be physically hit to be abused. Abuse can be any type of treatment that makes you feel that you are not important and lowers your self esteem.
Abuse is not so much a disease or condition as much as it is a choice. The abusive person usually was exposed to abuse of some sort either as a victim or as a witness, when they were growing up. The victim probably was as well. Sometimes the abuser is someone who has anger issues and takes his or her feelings out on someone they feel is weaker than them.
Abusers can get better. But the key to any treatment working is that the person must want to get better. If they are forced into treatment, they most likely will continue behaving the same way they do now. There is no amount of fixing or trying to make them feel better that will work. They simply do not see their behavior as a problem unless they work through the denial and realize that they need help. If they are not willing to get help, then they usually abuse anyone they are in a relationship with. So if you leave, he will most likely abuse the next person. But keep in mind, you are not responsible for his actions. He is. You are only responsible for getting yourself out of this relationship.
Your partner may very well be depressed if he lacks interest in anything. This can make the abuse worse because he will take his feelings out on you, rather than coping with them in constructive ways.
It does sound like you need to get out of the relationship. If you do leave, make sure you have enough support to help you through the transition. There is a lot of help out there. Here are some links to help you:
Think about joining a support group to help you cope. The Helpguide link above has resources to help you find a group in your area. Also, rely on trusted friends and family to help you. You will need the support until you are able to get back on your feet.
Consider counseling as well. It will help you address the issues that involved you in this relationship in the first place, so you do not have to worry about repeating a similar relationship in the future. Talk with your doctor for referral, or if you attend church, speak with your pastor. You can also search on line at http://therapists.psychologytoday.com/rms/. Also, contact your local community mental health center for more resources and groups available in your area.
Here are some books that will help you as well:
It's My Life Now: Starting Over After an Abusive Relationship or Domestic Violence, 2nd Edition by Meg Kennedy Dugan and Roger R. Hock
Why Does He Do That?: Inside the Minds of Angry and Controlling Men by Lundy Bancroft
No Visible Wounds: Identifying Non-Physical Abuse of Women by Their Men by Mary XXXXX XXXXX
Finding Your Way Through Domestic Abuse: A Guide to Physical, Emotional, And Spiritual Healing by Constance Fourre
You can find these on Amazon.com or your local library may have them for you.
I hope this helps you,