adobe premiere pro keep lagging

hello. my english might be low, so hopefully you can understand me.

i am using premiere pro cc 2015 for my club project. it was good before this, but it going keep lag after i put my laptop in sleep mode and let premiere pro running. after i on the laptop, this problems happend. i try find the solution by google it. i had try clean my cache files, but it did not give any change. it still the same. moere sad is, my media player like gomplayer also lag suddenly,same goes to vlc media player. before this(a day after the problems start), the project file became white, it didnt show the ikon for the project(hope you know what i mean). so, until now, i don't know what else to do. really need your expert skill to help me finish the club project.

i'm susing: acer one 14 | intel core i3-5005U (2.0Ghz, 3MB L3 cache) | 8 GB DDR3 L Memory  | 1000GB HDD |