I need to know what engine you have. Also what have you done and what has been checked at this point?

3.1 L engine;; Nothing has been done. I check all my fluids and the ground for leaks, but no visual leaks. I know zero about cars besides the basics;; My dad usually takes care of everything, but i'll be taking it to a shop Monday morning.

Sounds like you may have an intake leak. Meaning the intake gasket might be leaking into the cylinder so the engine is burning the coolant not leaking it. Could be a head or head gasket too. So have the shop check it and do a chemical test before just replacing parts. The chemical test will tell you weather or not it has cumbustion gases in the radiator if it does then it is a head or head gasket, it not then it maybe an intake or intake gasket leak. This manifold is also known for the throttle body leaking coolant into the intake too. So there is your heads up hope that helps.

Thank you! Is this going to be pricey?

Well that all depends on what is found to be wrong. If its an intake leak then it should be a few hundred if its heads or head gaskets then around a thousand or more. I would not worry to much untill you have the chemical test done. Keep in mind that these intakes do have leak problems so we will see.

I freaked out and took it yesterday;; He said there were some leaks around some gaskets causing it.

Good that shouldn't be so bad. Let me know how it goes. Have a great day.

The more & more my car acts up, the more i read about blown heads/leaks around head gasket. In turn, the more & more i think my mechanic is an idiot. Now it has started missing along with everything else. I'm positive it's leaking around the head gasket;; So tonight i'm going to try a sealant before giving up on my car. Do you have any experiences with these? I'm leaning towards K&W, but that is upon the many reviews i've read.

Go with the bars leak tabs. They are 6 tabs that come in a package it is what GM does when its just seeping. The miss may be part of the problem and may not be so lets do the tabs first.

Ok i'll try that first. How many do i use? Thank you so much by the way! :)

Didn't do anything :/

Was affraid it wouldn't. I still think is maybe an intake leak, it is common on those.