catch dog catching dogs HELP

first time other dog ran up showing agression i had him on the leash and pulled him back and other dog jumped him second time other dog danced around him all brissled up i caught mine other dog jumped hard to keep a dog off yours by yourself.i also feel hes being protective of me.third time he was loose and neiter of us were looking.but other dog has been known to start fights with previous owner.so idk.we didnt have a break stick if i need him off a hog i cut its ear off guy wouldnt let me cut his dog.i finaly used my kbar to break him