I hv this urge to cut myself using anything sharp. it's not like i'm depressed but it just happen when i'm holding those sharp thing. am i crazy?

You are not crazy: But you have a metal condition that needs to be addressed. Please see a mental health professional for an evaluation. Cutting is often a way to distract from feeling we don't like to feel. There is much that can be done to help. Peace and good health.

OCD?: Is it an urge or an obsession? There is a difference. An urge or impulse involves a desire or intention to do yourself harm. But an obsession is an unwanted anxiety-producing thought. It may be ocd. Whether it is ocd or an impulse to hurt, see a psychiatrist for an evaluation and possible medication. Cognitive - behavior therapy is an additional treatment to consider.