Also essential is that you are not lacking any vitamins or minerals so always make sure you are supplementing with a vitamin designed for males.

Zinc is also essential for males so make sure you have enough of this.

Hope this helps!

Alcohol is well known to reduce libido.  It may increase your mental desire, but physiologically makes it harder (er, softer?).
MAOIs can also drastically reduce libido.  The odds are lower with the newer medications, but it still happens.  Also, interactions between anti-depressants and alcohol (a depressant) can complicate all sorts of things.  It's generally not a good idea to mix the two.

I would recommend cutting out the alcohol.  None at all would probably be best in the short term.  If you feel you must drink, try to keep it to a pint or two every other week, or something like that.
If you don't see a change after that, then definitely tell your doctor about your libido problem.  He will very likely try different types of anti-depressants to eliminate the side effect.  He may also check your testosterone levels and thyroid activity, as those could also lead to this type of problem.