Am I hacked?

So 2 weeks ago I got a Denial-of-Service attack. A person in Omegle flooded "YOU HAVE BEEN HACKED" in the conversation where I was. When I got that attack, my computer was slow for 2 hours, and even after restarting my computer was slow, and the browsers stopped working or got slow right after opening the browsers, but then they worked again, but the Internet was offline, and I saw that the WLAN was disabled, and I enabled it again, and the computer was doing the wind noise and my computer was quite slow too. Then the next day I got that attack again, and then the third day someone said that they saw what I look like, and I got really scared, and then after the third day my computer started doing some Windows updates and there was a BIOS update too, and then after the updates, I've seen that a weird program tab on the task bar with a icon of a question mark on a circle appeared for 3 seconds 2 times, and then last week the CyberLink programs opened by themselves, and now there is a little window where it says "Data disk" and it's a CyberLink program, and it's waiting for a data backup CD so I can put my files, pictures, videos, music, etc. in the CD so they can be backuped, and when I shut down my computer once, I saw that my webcam program was open even though I didn't open my webcam program, and I also checked that if there are some weird IPs on my computer by closing the browsers and chatters (Skype, MSN, etc.) and everything that uses the Internet, and today I found one weird IP that I don't know who's is it, and today my computer's screen went black about 5 times and then when the computer's screen stopped going black, I saw a window where it said "System settings have been changed. Please restart." or something like that. Am I hacked? And can any hacker do the remote thing to the victim so the hackers can see the victim on the camera and the pictures of the victim without the victim opening any link or file? And can the hackers find out the victim's website accounts even though the victim doesn't open any link or file on Omegle or anywhere? I didn't open any link or file on Omegle or anywhere.

I am not sure if this is the right category for this message. If it's not, then can you move this to another category?