Hello and thank you for using JustAnswer Health.
Just from what you have said, your boyfriend has what is called a Personality Disorder, probably Narcissism and is abusive to you.
As far as the ability to change, it would actually probably be to your favor if he was Schizophrenic, because there are medications that can help in that case.
There are not medications that can completely help a Personality Disorder. In fact, studies have shown over and over again that an abusive individuals tend to increase in abusiveness over time, rather than to decrease.
You may have what could be called 'Co-dependency'. With this condition, the individual often themselves grew up somewhat neglected or abused, and may have had an abusive, alcoholic or addicted parent. Thus you grew up constantly wanting to help others and to please them, and without ability to recognize when some one is being abusive to you. Although you feel 'love' for him, this is really your desire to be loved yourself. You will never get it from this individual, and until you can see this you will continue to be abused by him.
Therapy can help you, but it will not help your boyfriend because his disorder is 'fixed' and he is not able to take feedback and change.
I will provide you some resources so that you can read more about these conditions, and hopefully you will get therapy and support for yourself and take care of yourself.
Here is information about Narcissistic PD (note that you can click on the tabs at the top of the page for more information than what is on the first description page):
Recognizing and dealing with an abusive person:
Signs of a codependent relationship:
I encourage you to check out several more of the sections on the helpguide.org website - there are links to help lines where you can talk to someone and get referrals to groups and help in your area. Consider reading the sections on relationships, addiction, self-esteem, in addition to the links I've provided you above. It is very possible to take care of yourself you will need to separate from this individual. But if you do not see that yet, then the first step will be to protect yourself by reading the information provided. (The helpguide.org website appears to be down right at the moment - probably for maintenance, do try them later if they are still down when you try to go to the website - they are the best online self-help website there is):
If you have questions or need clarification please reply to this post so that I may assist you until you are satisfied with your answer.