Is it normal that i use orgasm to help me sleep at night?because it's very relaxing & often made me feel sleepy afterwards.why is that?

You are fine: The cycle of sexual excitement whether with a partner or by self stimulation includes a phase of recovery following orgasm which allows a person to recuperate and "recharge" before a renewed sexual effort occurs. This is perfectly normal and you are responding as you should per Mother Nature. Further questions can be directed to me at www.healthtap.com/drsaghafi if I can be of assistance.