When my husband passed away my dog became overprotective. He will not let a man near me or speak to me. On walks he will lunge and drag me to the ground when he sees a man. It is difficult because he is very large and easily pulls me off my feet. I had to stop walking him. He still gets plenty of exercise because I have a large fenced yard and play ball, ect, but I like the walks. Any advice?
One way to deal with overprotective dogs is to create a positive association with whatever triggers the undesired response. In this case you want him to associate men being around you with good things (e.g. treats, praise, or play).
Start the process in a controlled environment at a distance that doesn't set him off, then slowly decrease the distance between you and the man until you get within conversation distance. This could take several sessions. Once the dog tolerates a man being in close proximity to you, you can have the man give treats to him as well.
During desensitization training reward the dog with treats and/or praise (or anything else that he highly values) in quick succession to keep him focused mainly on you, and to create the positive association.
Hopefully this gives you an idea of one way of approaching this issue.
Good luck!