Resource Guarding & biting owner

Hello,

We adopted a male French Bulldog (at age 2), had him neutered right away and after about 6 months in our home, he suddenly became very territorial over a basket of leashes that we use to walk our 2 larger dogs. He has never had an issue with the basket before. He now gets extremely upset and aggressive if we attempt to take the basket or go near it and has actually leapt at my face and nipped my fingers. Our large 75 & 90 lb dogs are generally afraid of him. One of them was too scared to walk into the house today. We have never owned an aggressive dog and are afraid that he will start finding other items on which to fixate. We would like to try correct this behavior ourselves if possible but if your thoughts are that this can only be managed by a trainer then we will look for one immediately.