When you read you probably don’t look at individual letters and sound out the word in the same way as when you were learning to read. Instead you recognize and mentally say the word rather than the individual letters. You need to take this a stage further.
Stop verbalizing the words in your mind. You don’t need to do that just as you don’t verbalize each individual letter.
Recognize a whole phrase or sentence rather than individual words. It takes a little practice but it can be done and becomes instinctive.
These two advancements will improve your reading speed dramatically.