Can’t sleep

I’m 4 weeks pregnant and can not sleep. I’ve smoked weed for ten years and when I found out I was pregnant I stopped.. last night was the worse night and I couldn’t sleep. I took two pills off of a blunt and felt better and slept better. I’m nauseous, my body is changing and I can feel it. How can I sleep without causing harm to my baby. I only smoked a little last night but I don’t want to do that again. I need a safe alternative. Please help I am a first time mom