Losing power is a rather broad description. Is the engine running or does it quit? Is it that the engine is running, but pushing on the accelerator doesn't cause the car to go faster? I am thinking that perhaps your cvt is overheating (either because of low levels, clogged radiator, or just contamination. Your cvt fluid should be a light green. If not, then it is time for the filter to be changed and a drain and fill. Remember to check the levels with the transmission thoroughly warmed up and on level ground. Let us know.

 

I'm going to assume the entire car loses power not just the engine or transmission. In that case check that your battery terminals are not corroded.

 

Great way to rule out transmission overheating is to invest in an OBDII dongle and an app that can read CVT temperature, great app is CVTz50 from Google play if you're on android. App is $4.99. Well worth the price.