Could Anxiety mask the symptoms of ADHD?

I'm asking because I have always known something was wrong with me, though I've never seeked medical help. Over the years, what I believed to be social anxiety at some point turned into a realization that I have been suffering from full-blown anxiety all my life.

About six months ago I was offered to buy some amphetamines while out drinking with some friends. A month or so prior to this, my best friend, who a few years ago suffered from Psychosis and eventually got diagnosed with Paranoid Schizophrenia, came to me and told me that he had just taken amphetamines, and that he felt it helped with his psychosis (which I at the time thought he didn't even experience anymore episodes of). Just a week before I got offered the amphetamines, he came to me again and told me the same thing, denying that he had told me already when I confronted him about it, and saying that he had just recently taken it (WTF).

So I thought: what the hell, I might as well try and find out what it is like so that I can better argue against him taking it (Which seemed impossible for me at the time ... And still is).

I brought the dime bag home, and my two friends whom I was out drinking with, joined me in taking it.

So, my experience, as best as I can explain it, was as follows:

• I ingested it through the nose, and could immediately feel a rush.

• After the rush I was stricken with what I then could only explain as complete and utter silence.

• So I sit there for a few minutes, taking in what felt like nothing, and which made it apparent that what I felt before, and has always felt, was something.

• Eventually I realize what the "nothingness" was. Throughout my life my thoughts have always run wild. If I am to explain my mind in as simple terms as I can it would be: a) My personality with the thoughts I myself choose to think, and b) A constant chain of thought that goes at a speed of at least 1.5x my normal thinking and talking-speed, which I myself can't control (can't chose to stop, or direct it at some concept) and rarely are able to remember much of.

• After some time inside my own head, I started to notice the conversation my two friends had. They were talking about a gaming-club they are running, and I noticed that even though they both made solid points, their conclusions were all blown-out-of-proportion. One moment they were talking about how it would be "free for all", and in the next they started talking about monetizing it with a yearly fee, not even noticing the apparent conflict with what they had just discussed and agreed upon. Eventually they became seemingly obsessed with the thought that the name (Which I made up for them) of their club would make them big and rich, and that's when I realized that what I am experiencing is not at all what they are experiencing. To me it looked like they were showing symptoms of mania, though I'm no psychologist.

• The effect lasted for about 10 to 15 days (Without taking anything after the one night. I gave the rest to one of my friends who asked if he could buy the rest), and then I experienced one day where thinking like I had been thinking in the past 10+ days became very hard. Possible, but very hard. On day two, I was tired in a way I've never been tired before (Thinking became next-to impossible, so going to work was hell, as was having a simple discussion with a colleague. However my body wanted nothing more than to go out for a run and get physical. I'm a lazy guy, so this is not like me at all). On the third day, the chain of thought was back, and has been ever since.

This was six months ago, and I must say that the time after have been really hard for me. It's like I know I now feel the same way I did before taking the amphetamines, which was fine then, but after having 10+ days where I could actually think straight, feel right, and do stuff like watch TV-Series and actually pick up on stuff to the point where I am able remember everybodys names, I want nothing more than to get that amphetamine into my body again.

However, I know that those feelings are the feelings of a drug addict. I feel like I need it, and that scares me and makes me doubt that I actually have ADHD, or some other brain anomaly that amphetamines would help relieve. That I'm making up the symptoms, believing them and thus making them true.

The thing is, taking amphetamines also "removed" my anxiety. I've got some physical symptoms from time to time, but I can't really say that anything scares me anymore. I feel comfortable around people now, and the only thing that I see as a problem, is that I feel like there is nothing keeping me from just running out the door, never looking back at my boring-ass job. I've felt this in every single job I've ever had, and I believe the only thing that has been keeping me from just running out the door, is the anxiety, in the form of an extremely strong authority-complex, which I no longer possess at all.

Here are some other symptoms I experience:

• I must often use all my focus on something just to do it right, thus making me unable to notice other things. This is especially true if I do something new, like a new and unfamiliar task at work for instance.

• When talking to people I have trouble following what they say and I often end up having to ask them to repeat what had just been said.

• Sometimes I may be very focused on one concept, which can make me confused if someone brings up a second concept that isn't related to the concept I had on my mind. I might either not understand their phrasing at all because I'm to focused, or I might think that it is related to the concept I was thinking of, even when it should be apparent that it is not.

• When reading I tend to not register important words in sentences, making the sentence either faulty (I'll notice) or different (I probably won't notice).

• I am not able to form images in my head or hear any voice in my head related to something I am reading, if I am reading while trying to form them, though I may be distracted from what I am reading because my thoughts run wild or other, unrelated images pop in to my head.

• When I am about to write a story, I can form a complete world in my head. In fact, I have already developed three complete stories. Though after writing the first sentence of any of them, I get stuck. I feel like after doing so, the form of the whole story is set, and it somehow feels incompatible with what I have left in my head. This only relates to works of fiction. Any writing of logical nature, for instance the explanation and interpretations of events, like this piece, is easy, but only if I don't have to organize the information after some kind of model.