Help me, please! My puppy is sick but I don't have the money to take her to a vet...?

I woke up this morning to my puppy vomiting this white foamy stuff and she has had diarrhea the past couple days. She's still playing normally and she's not lethargic, so I don't think it's parvo. She's about 3 months old. She's also had these yellowish green boogers that turn crusty on her nose. Help please! I don't have the money to take her to the vet but maybe there's something I can buy to help her?