After having mass disruption for a few days, my connection is now back to stable again. I can get 70-80 KB/s when downloading from foreign site and sometimes i can even get 106 KB/s (the site i know are Microsoft and Symantec). For local site which are connected to IIX or OpenIXP, i can get around 100 KB/s.
Actually, until this morning, my connection was still in bad condition. I called Speedy Care, not 147 (this is Customer Service). I asked them whether the mass disruption has been fixed or not. They said that they have fixed it and there were no complaints anymore about this. Well, mine is still having problem . I asked them whether i have to restart my modem and they said it isn't necessary because the routing will be redirected automatically.
I'm doubt that, since my connection was still very slow. So i turned off my modem and turn it on again, but my DSL didn't turned on (just like my problem few days ago), so i retry it again and this time, it works and the connection is fast. Now i can do my work, my project, and my thesis again
Let's hope there won't be any problem again in the future.