Fussing during sleep

Hi mommy my boy is 6 months old. Recently during his sleep I realized he like to fuss a lot. I have latch him, change his diaper but still he would cry murder. He like to sleep side ways at night, but always fuss when his position was not right. Hence I have to carried him to pat him but his eyes was totally shut and then he starts to fuss again. Any mommy experience this?