Help really nervous about milk production!

Falon • Mother of a one year old baby girl ❤️
So as of Tuesday I've started giving my Little girl a tablespoon of cereal at night and I just pump my breast milk to mix it. So tonight when I went to pump out milk I couldn't get even 1/4 of an oz and she was latching and sucking then loosing it because I assume I don't have any milk for her so my question is has this happened to any of you before? I'm really nervous that my milk isn't going to come back and I'm going to have to switch to formula. My little girl is only 3 months and I can't afford formula