Will this help me sleep? 1 mg of Chlorpheniramine Maleate - Antihistamine. Nightime cough pill split 1/2?

FIRST OFF, I KNOW THIS ISN"T WHY I SHOULD TAKE THIS... But I've been laying in bed 2 hours and cannot sleep. I have mild insomnia and this only happens on rare occasions. I do not take nighttime meds to go to bed ever, except now cause I need to get to sleep!