First I am sorry you were bitten, I hope everything heals well for you. But I ask you PLEASE do not put your dog down. All dogs bite. of course the bigger the dog the more problems it will cause. There are many NO kill animal shelters and breed specific rescue groups out there that will take you dog and try and rehabilitate it. If there is an aggression problem especially with larger dogs they will put it to sleep. As you can see from my avatar I am into Rotties, but I have had many aggressive dogs growing up mostly Huskies.
Please consider this, below is a short list that I googled. Any one of them will be glade to help you or take the dog off your hands. What ever your decision good luck.
http://www.barkbytes.com/RESCUE/bulmas.htm
http://www.geocities.com/fjones7tn/other_sites.html
http://clubs.akc.org/aba/rescue/resvol.htm
http://www.mastiffrescue.org/contact.htm
Please consider this, below is a short list that I googled. Any one of them will be glade to help you or take the dog off your hands. What ever your decision good luck.
http://www.barkbytes.com/RESCUE/bulmas.htm
http://www.geocities.com/fjones7tn/other_sites.html
http://clubs.akc.org/aba/rescue/resvol.htm
http://www.mastiffrescue.org/contact.htm