I am seven years post surgery and I still have what I describe as a "metallic" taste in the back of my mouth. It has improved over time, but still there. I started out eating very plain foods after my surgery - mashed potatoes, milk, pancakes with nothing on them etc. I also could not tolerate soda - tasted like just the seltzer water. After things improved some I found a strong gum that I use - Eclipse, spearmint - but even so have to change to gum about every 30 minutes because it takes on the metallic taste.
At the beginning I did a lot of research to see if I could get rid of this taste. I even had a "tympani nerve" snip, which basically cut the nerve that controls the taste buds in the rear of my mouth on the left side. Well, that did nothing so I followed up with an expert who has done studies on this issue - what I was told is that I have a "phantom taste" - basically a form of nerve damage from the surgery - my brain is sending the signal but there is not necessarily anything causing the taste. Over time this has been one of my most frustrating issues - especially at night or when I try to lay down - I have the taste going down the back of my throat and the nauseated feeling.
Currently I use a mix of water (20 oz) 1 tsp of salt, 1 tsp of baking soda and I try to rinse and gargle at least 3 times a day. This helps for a while. Also, I noticed in the morning before I would eat or stimulate my saliva glands with smell (like cooking bacon) I would have less of a problem.
If you are just having bad taste when you eat, that hopefully will clear up over time. If you are having constant bad taste you may want to continue to research for something that will help make more tolerable. Best of luck!