Is it wood or drywall?

In my personal experience, it sounds like you screwed directly into drywall and didn't anchor into studs.

I would recommend checking the material you're screwing. If it is drywall, use a drywall anchor which requires pre-drilling holes before placing the plastic insert into the wall.

If it is wood, I'd recommend a stud finder to anchor into the stud of the wall.

There's a lot of variables. The first is ensuring it's not drywall. A simple screw in drywall will not hold much weight.