I think reading ahead is common advice, but maybe a little bit of a misconception of what's actually going on.
If we take normal reading for example, when we read words or sentences we are not reading letter by letter but we are glancing at the word we recognise and effectively mentally sounding it in our head.
When we come across a word we have not seen before we tend to slow down pronounce the word (even in our head!) and then next time we start recognising it faster and faster until it's added to the vocab.
This is obviously assuming a sound knowledge on the letters of the alphabet and how they sound together.
This is what actually needs to go on in music. Consider the key of the music to be the language/alphabet and the series of notes to be the words.
Now where it differs is music does not spell recognisable words, so what we do differently is not try and sound the words, but look at the shape of the progression of the notes, the different spaces in between and then voice that in our head.
Seeing a melody going up or down is easy, but learning the spaces in between is where people struggle.
If you are trying to read it note by note, it's like reading a sentence letter by letter it doesn't work. Now don't be discouraged, that at the start, you will read it note by note just like when we practice reading words for the first time, but just be aware your aim is not to get faster at reading the single notes, but to recognise the spaces and how it sounds.
It would be impossible for you to look at the right hand note, look at the left hand note, remember the key, remember the tempo, remember the rhythm, recognise the actual notes value and then the dynamics, and keep refreshing that every single note!
Many people will tell you that practicing chorals helped their site reading dramatically. (FYI these are typically passages of music primarily made of chords) and it is again because you have to quickly recognise the spaces between the notes rather than the notes themselves
You will know when you have improved or even at least mastered the fundamentals, as you can then just look at the score freely without confining that note on the 2nd line in the treble clef to be a G and the note on the 3rd line of the treble cleft to be a B, but you will just read them as 2 notes, a 3rd apart.
The final test will be to take a piece of music and transpose it on the fly.
I tend to waffle on, but I have seen you on the forum before and you seem to have lots of questions for improvement, I think you have a teacher, but I thought i'd throw in my understanding of sight reading in hope that it helps.
A little off topic but - This also then bridges another theory that "blocking" a method in which you take a series of notes in a melody and play them all together in a chord and practice that chord, really helps you accurately learn the piece, because you are just learning the spaces for your fingers.