Hello there,
I'm sorry to hear you are experiencing a difficult time with your boyfriend. From what you're saying, it sounds like he's uneducated about self-harm. Maybe he meant to say you're suicidal and psycho intentionally, but also maybe he believes this is the right way to stop you from cutting yourself. It's difficult to tell whether or not your boyfriend cares about you since there's not much detail you gave about your relationship with him. From what you're saying, maybe you should consider leaving the relationship if he's being immature about what you're going through, or if you believe you can save the relationship, then go ahead and do so by talking to each other about the matter at hand.
Have you ever considered convincing him to educate himself about self-harm? I believe if you haven't done that already, you should consider telling this to him. That way, you guys can better understand each other, and everything between you guys won't be one-sided. Also, speak to a school counselor about this issue of yours. He/she may be able to help you, or refer you to someone who can help you with your situation. If you're having thoughts of suicide, consider talking to someone close to you about it (i.e. family member, friend, boyfriend, etc.) and seek proper treatment. In case that isn't available to you, then call a hotline number that can be found on the TeenHelp website. Here's the link:
http://www.teenhelp.org/hotlines/
Remember that suicidal thoughts shouldn't be taken so lightly, and get the help that you need. I wish you all the best in your situation. Take care of yourself.
-Batman