My 11yo was a late reader. We got to a point where I started having him sit on the couch with me and he would read me a page or two and then I would read to him. If a page was too difficult or he felt overwhelmed, I would have him read me one sentence and then I would read a bit. Gradually, he would begin to read more and I would read less.
I did have a certain amount of time scheduled for reading aloud. If he began to get too frustrated we would stop after I felt he had made a good effort, even if it was less than the scheduled time. In your situation I wouldn't want him to get to the point of tears.
If I remember correctly, we didn't start doing this until he was about 8. He is reading at grade level this year and he loves to read! Hang in there. He will get it.