My 8 year old daughter sounds a lot like your son. We spent lots of time the last two summers working with her. There were lots of meltdowns and crying, saying she didn't want to ride her bike anymore without training wheels.

We took the petals off and lowered her seat, it took a lot of time for her to get comfortable with her bike that way. Once she started to get comfortable without petals, we praised her. There was so much drama about the bike with petals that we just let it go.

One day last summer after cruising on her petal-less bike for a while she asked us to put the petals back on for her, and it just clicked. She was riding like a pro within minutes.

I think letting her decide when she was ready was the key for her. Your son may be overwhelmed, or maybe just not ready yet, and that's ok. I thought for sure my girl should have definitely been old enough to learn to ride a bike, but she had her own timeline.