What's the Name of That Book??? discussion

I read this book decades ago, most likely between 2000 and 2018. I am not sure about when the book published. The book might be part of a series.

The mc in the book I looking for have trouble with learning, he has trouble writing.

One day he somehow got into another world, there his style of writing or rather his learning issue have significance.

If I am not mistaken, he can travel back and forth. I could be wrong about this.

The world have magic.

I remember vaguely about seeing priest and magic potion mentioned in the book.

There was a moment where a king said the greatest defense is offense.

I might be wrong, but I remember in the series, the mc looking for potion.

In the book, the mc in original world write in gibberish, but somehow, it has significance in the world he travel to.

I think there are also some sort of prophecy, I not sure though.

I'm not sure this is an exact match but it came up in a search and I thought I'd mention it just in case! Spellwright by Blake Charlton (first book of a trilogy).

From the reviews there are similarities with your description. Not sure about the two worlds though!

The protagonist in City of Secrets, by Mary Hoffman (2009) is dyslexic and travels to another world.

Alcatraz Versus the Evil Librarians, by Brandon Sanderson (2007) similarly features a dyslexic main character who discovers an alternative reality.

Theresa Breslin's Whispers in the Graveyard (1994, but re-published 2007) is set in this world, but, again, the protagonist is dyslexic and fantastic (horror) things start to happen.