My cat is throwing up, is she sick?

My cat threw up earlier and she has been very irritable. She threw up last week too but has been active until today. Today she's just laying around and she seems to be growling at nothing at all. She'll growl and hiss and clenches her body which makes her seem in pain. I gently touched her stomach and that seemed to be painful. Her breathing is kinda fast but its not too fast. She seems to be taking a full breath (in and out) every 1 to 2 seconds. She pooped earlier so she isn't constipated but I don't know. Is it just like a hair ball or something worse? I'd rather not have to take her to the Vet but I will if absolutely necessary. Shes barely a year old (hasnt had her shot)