CVT transmission issue

I feel your pain, having your car go tech on you isn't fun when you need it. The good news is from how you describe the problem it doesn't sound like you need a new transmission, just a repair. Most likely the slipping is due to the fluid leak, so you need to get that attended to. Transmission fluid makes the transmission work but it is also a lubricant, if you run it without enough for too long you will cause much bigger problems, meaning more $$.

The typical causes of transmission leaks are:

• Cracked casings: fluid is leaking from cracks in the body of the transmission itself. This is the worst case scenario as it really means the transmission is probably toast but fortunately it is not likely
• Cracked torque converter: this generally means you have to drop the transmission to get it replaced. The part itself is probably $150-200, labor the same, depending on the car it could be more. It's not that likely, but possible
• Cracked transmission pan: the pan is at the bottom of your transmission and is where the fluid pools. If you drove over a big rock or debris it could have developed a crack. It's not likely, but it is one of the best case scenarios, as a new pan and seal shouldn't set you back much
• Blown or degraded seal/gasket: this is the most likely scenario, and is hard to give an idea of costs because it ranges from cheap to expensive. Some of the seals are easy to replace, for example the pan gasket is a few bucks, and replacing it is 20 minutes work. The front seal would require the transmission to be dropped out

Bottom line is you need to get this to a reputable transmission shop so they can get underneath and have a look. Hopefully it will be a pan seal, but if not at least you'll know.

One thing to note: there are additives that advertise themselves as stop-leak miracles, however they aren't recommended overall because they are at best a stop-gap and at worst cause more problems down the line. From the sound of it your leak is big enough these products wouldn't even give you temporary relief, so my advice is to take it to a pro.

I would take it to a gm dealer. these transmissions have a part inside the top that's not terribly hard to get to that controls shifting. It has solenoids in it and they can get damaged from lack of fluid.