Insomnia while pregnant

In the past 2 days, I’ve gotten 3 hours of sleep. Im 24 weeks pregnant & I can feel myself getting tired but I can’t sleep! my chest hurts & I get lightheaded here & there. My OB isn’t in the office & neither is her nurse so a doctor can’t answer my question.. I’ve tried melatonin & Benadryl & neither helped .. I can feel myself getting agitated & annoyed & moody.. everytime I try to fall asleep, I will sleep for a hour(if that) & then wake up & then I sleep for 10-20 minutes on & off. I’m congested & nothing helps.. & I don’t think the not getting sleep is helping.. what can I do? Has anyone else gone through this ? when I go to fall asleep, I feel my heart start racing or my body jerks suddenly & it wakes me up.. when I’m finally able to fall asleep, I can only sleep for 20 minutes.