If you can see a psychiatrist without a referral from your personal physician, I recommend you do so.
He/she is best qualified to diagnosis emotional/mental disorders.
However, it is up to you. Maybe you will feel more comfortable in your doctor's office, discussing your fears. Then going on to a specialist. I believe many doctors in general practice hear their patient's worries about symptoms they have found online. This can work against you to a point. They may tell you to stop checking out symptoms online and send you on your way.
When you see a psychiatrist, you have the advantage of talking with a specialist; one who deals with every kind of mental disorder. Mine asks me not to rely on what I read online..LOL. Good luck.