FPS suddenly dropping

Please help

In last week, I logged on my account and suddenly the fps always dropping in a stable 59-60 dropping to 43-46
I don't know what's wrong, I even tried set the setting to default but problem still there
I played BDO in couple of months ago and there's not a single problem in FPS but now I experienced it since last week

This is my specs
OS Name Microsoft Windows 7 Ultimate
Version 6.1.7601 Service Pack 1 Build 7601
Other OS Description Not Available
OS Manufacturer Microsoft Corporation
System Name USER-PC
System Manufacturer Gigabyte Technology Co., Ltd.
System Model H81M-DS2
System Type x64-based PC
Processor Intel(R) Core(TM) i5-4460 CPU @ 3.20GHz, 3201 Mhz, 4 Core(s), 4 Logical Processor(s)
BIOS Version/Date American Megatrends Inc. F2, 06/08/2015
SMBIOS Version 2.7
Windows Directory C:\Windows
System Directory C:\Windows\system32
Boot Device \Device\HarddiskVolume1
Locale Indonesia
Hardware Abstraction Layer Version = "6.1.7601.24059"
User Name User-PC\User
Time Zone SE Asia Standard Time
Installed Physical Memory (RAM) 12,0 GB
Total Physical Memory 12,0 GB
Available Physical Memory 8,55 GB
Total Virtual Memory 23,9 GB
Available Virtual Memory 19,8 GB
Page File Space 12,0 GB
Page File C:\pagefile.sys

And this is also my GPU
http://gpuz.techpowerup.com/18/11/22/ngf.png