A somewhat crude fix that you may not love the aesthetic of but will stop it from happening would be to anchor the column off with a guy wire and turnbuckle.
For a bit more robust solution you could dig a little concrete foundation off to the right side and set an anchor bolt in then with rotary hammer and wedge anchor secure another tie off at the top side of the column, run some cable between them and add a turnbuckle to adjust it. If you don't want to pour concrete you could drive a metal t post in deep at an angle.