Big bug

Dear all,

When I'm playing Minecraft 1.8.7 (survival) it bug's really hard. Whatever I do it's in "slow motion". Also when I waant to load a world it takes thousand of hours to load. Can someone help me please?

ColinFreeze

PS: this came on my screen: [20:36:58] [Client thread/INFO]: Setting user: ColinFreeze

[20:37:06] [Client thread/WARN]: textures: dropping miplevel from 4 to 0, because of minimum power of two: 1

[20:37:52] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 24250ms behind, skipping 485 tick(s)

[20:38:01] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 8668ms behind, skipping 173 tick(s)

[20:40:54] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 166188ms behind, skipping 3323 tick(s)