Why am i allways paranoid?

i insist on keeping every door shut, locked, and bolted! also i all-ways try to keep the window shades shut because i believe some one is watching me or out to get me. when i hear a noise of any kind i turn real fast watch the door and try to find something i can use as a weapon. i try to find something i can use as a weapon no matter what room im in. also i try to keep all the lights on please help me!