I am so sorry to hear of the problems you are having with your pup but it does sound like you are starting to make a little progress. I believe that the food handling by you while he is eating is very important to establish dominance.
Every pup we've ever gotten we've started immediately with with training at the food bowl. First I or my husband would put our hands into the food bowl while the pup was eating. Taking the bowl away then giving it back again. As long as that went well we would then sit with my kids on the floor and we would all put our hands into the food while they were eating. Messy but effective. We then would proceed on with treats - taking them away, giving them back.
We ran into a problem when we got our St. Bernard pup. She was about 4 months old at the time we received her. She was very aggressive if you went near her bowl, snarling & growling. I tried to use my firm voice with her but it didn't seem to work. The magic trick with her was my husband. He used his deep firm voice with her and she immediately backed down from the confrontation. I believe it was the deepness of his voice that made her rethink who was dominant. She is now 155 pounds and a big old mush.
My Daisy was fine with the food bowl but a little meanie when it came to anyone getting near her treats. She would bare her teeth and try to run away with it. Luckily, deep voice dad helped out again. They had a stand off. He went to take her treat, she snarled. He raised his voice at her, she bared her teeth then backed away and backed down. He took the treat away, gave it back, over and over. She turned out just fine after that and to this day is good about her treats.
Maybe it would help to have your husband help you with the handling and use his deep voice to discipline the pup.
Hope it all works out for you.
