Call the vet and they can give you info. If she's sounding like she's having issues bringing up whatever it is, it could be a blockage. The vet can also tell you if you should induce vomiting, but I doubt you should do that right now.

Well, it wasn't a blockage, thank goodness! Brought her in today and it was an upper respiratory infection. In addition to that she had a slight fever too but she's on antibiotics now. Hopefully all goes well!

I'd definitely call a vet.
Just as a reference, you can give your cat plain petroleum jelly to ease hairball passage.
Some of them like the taste and others hate it. But it's safe and doesn't cost very much.

I'd contact a vet immediately and see what they say. My girlfriend actually just lost her cat very recently. He has crystalline blockage in his urethra, and he was vomiting and, until he just flat out couldn't pee at all, it was very painful for him and difficult. We had to put him down because we couldn't afford the surgery, but we figured out what it was pretty quickly and got to act on the issue within 24 hours. I'm not saying that this is what's wrong with your cat... She seems to have a different issue, but it is crucial that you get her to a vet asap. The sooner the better. Should this issue be serious, immediate action could save your cat's life. Otherwise, it just relieves her of her discomfort sooner, which s just a nice thing to do.

I wish you luck, my friend.

~ Xena