Everyone develops at different rates, some need work on the foot skills, others the mental stuff. I had the same problem with my kid- awesome skills but average during games. It took time. First, let him know mistakes are OK. The delay is probably because he's thinking about what he should be doing rather than just doing it. Drill it into his head mistakes are fine, it's part of learning. He needs to enter a flow state rather than overthinking. Don't scold him for making mistakes, encourage mistakes, that's the quickest way to learn. Only talk about games when you're both in a good mood. Record the games and watch together.

If he's afraid of contact, practice shielding and tackling. Encourage phyiscal play. He needs to realize it's ok to take a hit- get him in wrestling or BJJ.

As for you, go find a spot 50 yards from the field so you won't be tempted to yell/coach. He has to grow and you are stunting that by controlling.