I don't know if this article best describes your dog's problem but this is a link to the types of preparation training, redirection, corrective halfter/leash apparatus and desensitization I would first try with a dog like you describe. Many sessions for a good two months should begin the fix:
https://www.aspca.org/pet-care/virtu...reactive-leash
and:
https://www.aspca.org/pet-care/virtu...erconditioning