I'm so sorry for the delay in our response, but I wanted to hop in here to make sure we addressed your concern. I can definitely understand the confusion when it comes to thermostat issues as it can be very odd to figure out sometimes, but I'm happy to look into this for you.
First off, I would suggest using the Compatibility Checker to see if your system is compatible. Then, if it is, I would suggest contacting a pro to come out to help you with this since I know that the Nest thermostat is not compatible with stranded wires, every wire has to be connected to the Nest Thermostat system.
Please let me know if you have any further questions or concerns as I'm happy to help.