I have used JB Weld for similar projects, with great results. It's a two part epoxy paste. A little goes a long way. Fill the hole, let it dry, and drill a new hole for the screw.
Pro tip number one: since JB Weld can be sticky and messy, put masking tape around the area to be filled.
Tip number two -- wear disposable gloves. JB Weld is hard to remove from your skin.
Please don't ask how I learned these tips.
2012 Fun Finder X-139 "Boondock Style" (axle-flipped and extra insulation)
2013 Toyota Tacoma Off-Road (semi-beefy tires and components)
Our trips -- pix and textAbout our trailer"A journey of a thousand miles begins with a single list."