Hi I get a bitter taste in my mouth very often. I have been having this problem for a very long time(more than 2 years) also, I feel that my tongue goes a bit dry at times and I suspect it gives out a bad odor. I am a smoker and smoke about 10 cigarets a day. Please advise.

I am sure the most obvious would be quit smoking.
Smoking can leave a dry parched feeling. I am sure it can leave a bitter taste too since it effects your taste buds.
This is an interesting article
Stop Smoking To Get Rid of Bad Breath | Cure Bad Breath