MacBook Pro 2016 Extremely Slow After Few Minutes of Starting Up

Hi,

I have Macbook Pro 2016 with Touchbar with following config

MacBook Pro (13-inch, 2017, Four Thunderbolt 3 Ports)

3.5 GHz Intel Core i7

16 GB 2133 MHz LPDDR3

1 TB SSD

I have following display problem that there are lines emerging in the bottom, I can still live with that but I don't know if these lines are causing problem and making it more slower.

I have disabled every login items, My mac disk is 700gb used. I have reinstalled Mac OS only thing i haven't done yet is erase drive and reinstall.

These lines grow as mac is on for longer time but not more than dock height.

Thanks for help in advance.