Cps case, advice?

A cps case was open against me because I tested positive twice during my prenatal appointments. No I wasn’t smoking during pregnancy I did smoke before I got pregnant but stopped once I found out. I also have another child and I’m so afraid they’ll take them away from me. The cops showed up today just to look around and check if they were safe and had enough food which we did and they were fine. I don’t know what to expect but I can’t stop crying and I definitely regret ever smoking in my life. I have to interview with the caseworker tomorrow, I’m terrified. Idk why me, I did everything right after I found out. I was even planning on changing my whole life around and quitting for good. Life is definitely not fair, my cousins smoked throughout their whole pregnancy and still continue to smoke and they never did anything to them. I’m so mad and disappointed at myself. I can’t have my babies taken from me. Idk what they plan on doing I definitely don’t want to make things worse for myself. Advice would be appreciated or any experience with cps.