Do you have a rope halter? That helps. I know this sounds mean but if the horse tries to bardge over you take a frim grip on the leadrope and back them up, if they move mover them back to where they were standing. Keep doing this until they learn to respect your space. And if they don't respond make if sharp yanks with the rope halter. I hope this helps you.
A good rider can hear his horse speak to him, a great rider can hear his horse whisper, but a bad rider won't hear his horse even if it screams at him. Millie and Archie my two beautilful ponies.