what can i do

i’ve lost so much confidence with this horse but i don’t even know what to do anymore i can’t stop loaning him because i love him so much but i can’t even hack him without him bolting and napping he’s 30 this year and always pushes to go home he’s not mine so i can’t change his bit he’s currently got a dutch gag but i hate them so use the snaffle ring it does absolutely nothing and i can’t even get him to stop with a one rein stop should i just use the next ring down?