Surprisingly, I heard a tiny gem of wisdom on The Jeremy Kyle Show. There was a teenager on there (18) who thought he was asexual and felt pretty depressed about it/in general. There were some things on the show which I didn't agree with and thought sounded a bit ignorant, but Kyle also said that sexual attraction can come later... or it can come in phases.
I read this statistic that said 1/3 of women go through a period in their lives where they experience no sexual desire. Regardless of sex, I think that stat shows how common it is.

Also, it can be easy to slip into thinking that, because other people seem to be having loads of easy sex all the time, and you are not, you're doing it wrong and must be asexual. It's okay to want to actually love someone first, or to get to know the ropes. I thought of myself as asexual for some time... but I think maybe it is a fear of the unknown, rather than sex itself.

Depression doesn't mean you're 'broken' or need to be 'fixed' - but I thought it might be worth it to mention that one of the major symptoms of depression is lack of libido. You probably know that, but sometimes obvious things slip our minds in the midst of panic. I also understand I might be totally off the mark since I don't know you!

I think that, you are young and not ready to be labeled yet. Whether you are asexual or not, you can understand yourself better with time, and the support of good people. Good luck!