After update my fps drops

[KuroKuroNeko]

I've been playing from head start, it've been 3 days, i got 0 problem with my fps, with my customize setting, i always have 50 and up fps in town and 30 and up during combat, but after update, i didnt change anything in my setting, and i only have 13~19 fps no matter if i change my setting to low or high ?
please help