Try steering with knees out and in (therefore bent legs) and/or steering with the handlebars and pulling/pushing on the bar ends with your arms
to tilt the bike towards the direction you want to go, i.e. the side you are currently falling towards.
Wheelieing took me a good many months to learn, perhaps even two years, I don't remember. But it was the Nineties,
nowadays people learn to sidehop over a meter in the first year.