I'm petrified of the dentist! So scared that I bit my dentist today.....?

So I'm 13 and I haven't seen a dentist dice I was about 8. U wasn't scared then so I don't now what happened. I think it's cos my teeth r so bad. They were fine when I last went, but it all went down hill. My gums bleed, my teeth are all a bit loose, they hurt all the time, and 5 are chipped. Today, I went again and he told me I need 5 extractions, 2 root canals and 10 cavities filled! I know, it's bad. Luckily, 3 of the teeth needing out are baby teeth! When he first got the cleaning thing to just wash them, I bit his finger really hard because he was doing it on a really sore tooth and it was hurting like HELL!!!!! I asked him to stop but he wouldn't and I just cracked. I ran out the office and ran hone and now in grounded for 2 months!!! What can I do to overcome this?????