All I can think of off the top of my head is to have patience and don't feel embarassed about not knowing something, it's the way to learn!
The names of the notes and which key they represent on the keyboard is something that will be memorized. If you're at the stage where you have to painstakingly translate each note, then that's what you must do. As you practice sightreading day by day, you'll see the same notes again and again, and you'll begin to know them by heart.
You could sit down and read sheetmusic note to note, not playing but just saying aloud what the note is (C, Bb, A, F...), taking as long as you need. It wouldn't take much of this before you have a good grasp of the written notes, where you can see a note and immediately know what it is.
Practice reading every day, be patient with yourself, take small steps and you will be there before you know it. Remember kids first learning how to read? everybody had to go through the stage of slowly sounding out each word, making mistakes, mispronouncing, learning new vocabulary...
Topic: sight reading