I agree with the doctors (and kim johnson). =/
I think that you should try all of the other options before making your mind up about the surgery. Needle phobia vs making a decision that will severely impact the rest of your life... I'd go for the needle.
I'm 22, I'm young as well, we're so young that our bodies aren't even fully developed yet. And you will feel the biological clock ticking in your head when you're closing in on 30. 3 years ago, I HATED kids - but now.. I look at a screaming baby with vomit all over its face and I think "awww i want one". I think it would be a bad idea to make such a definite decision before having tried -all- of the options.

Actually, I was on depo provera some years ago. I was only on it for about 8 months, but I didn't get my period (and no symptoms) for TWO years.
Please try that one. You could take benzos before being injected, I'm sure the doc will help you with that.

I understand your frustration though x.x