4k @ 60hz on MBP 2018?

Hello,

So I bought a LG 4k 27UD88 monitor for my MacBook Pro 2018 and I was really excited to get it, but all the excitement went away when the monitor arrived, i plugged it to my macbook with the USB-C to USB-C cable with which the monitor came and I can't get 60hz refresh rate, even the mouse cursor looks choppy and it's driving me crazy.

The 30 hz option is disabled as you can see.

What can I do to fix this? Acording to everyone it should work fine at 4k 60 hz using the cable the monitor came with.

Bonus question: Is it normal that my idle temperature went from 38º to 46º only because I switched from a 21:9 1080p display to a 16:9 4k display?

Thank you in advance!