You most definitely should try to do whatever you can to see a specialist, self-diagnosing is just where a lot of people begin, it's typically someone's first hunch or indication that they might be on the path to a label for their unique behavior and set of talents/interests. Do not just go find any doctor, the majority of inexperienced mental health professionals will misdiagnose you with depression or something. This happened to me when I was 22 years old and it nearly caused my death via suicide when I had problems with Wellbutrin, it made me highly suicidal and insanely depressed...ironically all because the doc thought I had depression. That is what those wonky SSRI type drugs do to people who do not actually have a chemical imbalance.
Look for someone who knows the differences between a spectrum disorder and more common mental illness issues. Those doctors are capable of sifting through real cases of Asperger's and cases of someone who might just be a NT who is suffering from other problems.
Do not worry, I am in the same boat. I have recently taken ASD seriously as a potential explanation for myself and my problems. I am in the process of wanting to find an experienced specialist somewhere in western Pennsylvania. I feel that Asperger's is more than likely what I have, along with ADHD, but I can't say entirely for sure on my own. Most of the online tests agree with me, but we know those only "go" so far. Whether I am Aspie or not is not so much what I concern myself with, it's that I know I am not NT and because of that, I would feel very at peace if I had a diagnosis of some sort, Asperger's or not. I can not accept the idea of being NT, I have struggled with socialization, obsession, becoming lost in thought and other issues far too long to know that I am not just NT. I tried repeatedly to become part of normal society throughout my teens and 20s, now at 27 I have a growing list of failed jobs and attempts at education that I believe could have been avoided if only I had realized that I most likely have an ASD.
I am happy to be seeking assessment, even if it is a bit late in life, I feel I am still young enough to right my ship and accomplish something and find success and happiness. At 18 you would do well to not slack on things, find assessment and go from there, a true specialist is your only real hope, tests and other people here on WP are only able to give you moderate guidance, a true professional is what you need to make sure. Do not be afraid of what you might discover, all you will really discover is yourself.