Alzheimer's disease or mental constipation??

My brain must be about 60 years old now. It's not functioning like it would in a 26 year old person. As I am typing this, I realised that I've even forgotten my age. I was pondering whether I'm 25 or 26. Oh god.......am I losing my brains or my mind??

I've been worrying myself crazy these days, wondering if I'm suffering from a very unusual early case of Alzheimer's disease. Not only have I been more muddle-headed & forgetful than usual, I've also been losing my ability to spell & articulate myself properly. Words that I knew I know would suddenly vanish from my mind when I want to use them. It would only be a great deal of time later before they'd surface. Many a times, I'd even need to look up a dictionary for them. It's not just English, but Chinese & Japanese too. How can I explain this problem...the words would appear as empty gray blocks in my mind & I know that they're just hidden in those blocks. They just refuse to be revealed at the crucial moment when I need them. I've lost the ability to explain, articulate, calculate (even simple counting sometimes) & who knows what else.

Or is it, I hope, just a temporary case of mental constipation? It is as quoted from a dictionary -an inability to articulate one's thoughts or ideas, resulting in significant psychological distress and frustration. I don't even know if this is an illness or what causes mental constipation. Whatever it is, I hope there's a cure or explanation (pray to God that it's not A.D) to the gradual degeneration of my mental abilities.