Loss of Power, EML Coolant draining quick

[ryan7]

My parents VW 2.0 (55 Plate) Passat has a couple of issues, possibly related.

There is a loss of power when accelerating but today it the speed cut down to 15mph, then it started to pickup again.

Also, the Coolant is draining away very quickly. Top ups are necessary every other day and that's with very little mileage. I've left the engine running and looked under the vehicle to looks for drips but can't see anything.

Are both issues related? What could be the cause and how much to fix?

Thanks for taking the time to read my first post. Apologies if something similar has been asked and answered.