Sometimes I ask myself a question, think about it, answer myself and then I go back and try to remember the question I asked and can't remember. If I think, "Oh the question was this," I ask myself, "am I remembering this right, or is that what I think I asked?" Then I get confused and drive myself crazy. Is this a form of anxiety?
I feel anxious just reading your question!
Anxiety can definitely cause difficulties in thinking clearly, and problems with short term memory. Other issues can also cause this, so I can't tell you for sure if it is only anxiety that is causing this problem for you. Talking to a therapist may help you clarify this.
Anytime we are unable to quiet the restless mind, we are likely to feel anxious, agitated or depressed. Over-dependence on the intellect - the thinking mind - to make decisions and guide you through your day, can start to make a person feel crazy.
There needs to be a balance between thinking/feeling/doing and Being. Being is the most important of all - and is the least familiar way to most people. I suggest experimenting with yourself - and see if you can make it your intention for one whole day, to let your feelings and intuition guide your movements and actions, and to not rely at all on any inner dialog with yourself. It may be easiest to first try this in a safe, stress-free environment - like hiking in a natural place. Meditation is also a great way to work on balancing yourself this way. And of course, as I always recommend - EFT is excellent for anxiety issues.