1) that's far too hot for any CPU - you need to improve your cooling. Check the brand of your CPU, confirm which socket it uses then buy a new heatsink/fan combo (also check the height of your case)

2) You can use a device like this: https://www.amazon.com/P3-International-P4460-Electricity-Monitor/dp/B000RGF29Q (which will tell you how much the whole system is using)

3) if cellular is your only option, I would do this: https://www.amazon.com/TP-LINK-TL-MR3020-Wireless-Portable-Router/dp/B00634PLTW. get a new sim card or add a data sim card to your existing plan