Memory problem. Like this before.

Suddenly from past few weeks I am experiencing something very stupid and annoying. I am a science student n I have never had problem with numbers or something but suddenly now I am finding problems in simple problems(normal 2 digit multiplication). I can't recollect simple spellings which I used to know, in that case auto correct helps me out. But in notebook I am having hard time. Then I spell words wrong(wrong I sense I know spelling but I skip letters n directly write last 2 or 3 letters). N during letters I write sometimes write letter 'a' as 'd', 'u' as 'y' n similar problems. Today limits were crossed when I got confused in number 3 ,like its written like this 3 or it is inverted. Please help. I can't remember names of ppl I meet n I forget things like what I had said, etc Usually these symptoms r of dyslexia but that ain't possible cause from childhood I was a bright student n never has problem like this before.