Of course you cannot self diagnose yourself with ANY mental disorder. You can take all of the online questionaires you can find....but you still need a professional to thoroughly assess you to determine what, if anything, you may be suffering with. I think you would be wise to stop chasing your tail, and just make an appointment, preferrably with a psychiatrist. They are the best people to assess and diagnose a mental disorder.
The good news is...even if you ARE diagnosed with something, there are all kinds of treatments out there...it's not like life as you know it would be over. Maybe deep down you're fearful of a stigma that may come with having a mental illness? That's a reasonable fear, but I can tell you, that a very large portion of the population is diagnosed with SOMETHING...be it depression, an anxiety disorder, OCD, bipolar disorder...or even more than one. You wouldn't be alone, that's for sure.
I have been diagnosed with panic disorder and depression, and have never felt stigmatized. In fact, I was pleasantly surprised how accepting so many people are. You'd be surprised to find out just how many people you know suffer from something, yet you never knew it. It isn't a reflection on you, or a weakness, or a charcter flaw. To me, it's no different than people having diabetes, or high blood pressure. It's a condition that needs managed.
MY advice to you is to seek the help of a professional who can sort this out for you, the RIGHT way. Best of luck.
Sorry for the triple post but I'm 99% my mom has depression and my dad has been acting more happy than usual.
I also worry that I have not said everything in there... And also my whole life I've been very shy and not social.