Ordinarily confession is to be oral… But say in the case of one who can not speak…the extreme example of a mute…there can be writing involved I suppose. (and I have read at least one opinion that says perhaps in an extraordinary circumstance…someone finds it impossible to say…due to breaking down into tears they could say “I confess this” handing it to him (and getting it back and destroying it) such I have heard argued by an orthodox source (regarding extraordinary situations where it is too difficult for the person…too burdensome)…It seems though that you are just having a difficulty we might all have…talk with the priest even about your fears…he has heard everything…and more…no need to be worried… you will do fine…).
But really we are to “confess” with our lips our sins.
In a circular letter from the Holy See in 2000 from the “Congregation for Divine Worship and the Discipline of the Sacraments” :
“In accord with the law and practice of the Church, the faithful must orally confess their sins (auricular confession)9, except in cases of true physical or moral impossibility (e.g., extreme illness or physical condition inhibiting speech, speech impediment, etc.) This disposition would exclude communal celebrations of the sacrament in which penitents are invited to present a written list of sins to the priest confessor. It should be noted that such innovations also risk compromising the inviolable seal of sacramental confession.”
By the way…I suggest you use the screen…