Traducció - Suec-Castellà - hjälp tack

Just nu sitter jag och skriver till dig = I´m sitting here writing to you right now

I've added the emphasis word mismo.

Not that I want to be a pain in the butt, but doesn´t what you have written mean "Right now I sit down to write to you" ?

Isn´t it possible to say (in Spanish) something like "Neste instante, estou escrevendo para você"
I know that neither Spanish nor Portuguese give emphasis to whether you are standing, sitting, lying down etc. when you´re writing (or whatever else the person is doing, as long as the position is not the main point or focus) and usually the part with the "sitting down" is left out in translation. "Jeg sidder og tænker på dig" would therefore usually not be translated to "estou sentado, pensando em você" but rather to the simpler "I´m thinking of you"

I know that Anita.
I was going to translate "estoy aquí a escrebirte", but you know, there's always someone to say that it's not the right translation (especially a few swedes here) so I decided to make it literally.

Ok, it´s your call. I would personally have preferred your first idea "estoy aquí a escrebirte", but you decide.