If your run performance monitor whilst playing (you can access it by pressing Ctrl+Alt+Delete), what are your graphs looking like?
I had a major issue running the game after upgrading my PC and I installed a brand new SSD (WD Black) and had constant 100% disk usage according to performance monitor.
Turns out that this particular hard drive wasn't actually 100% compatible with Windows 10 so my Disk Usage was constantly running at 100% with CS GO. The Usage was constant on the disk on Perfmon.exe and the response times was showing in the 1000ms + mark.
I tried everything including Registry Edit to ensure the disk wasn't falling asleep. Long story short, I ended up replacing the Hard Drive and this solved my issues. The OS ran well and so did CS.
Hope you get it sorted!