I am also on 40mg of Celexa daily. I have tried other antidepressants, all of which affected my sex drive. However, Celexa has not interfered with that part of my life at all. I've only been taking it for about a year and a half now, and have had no issues. Maybe its the interactions of all the drugs you take together. Or maybe your body is changing and buliding up a resistant to the long-term usage of this medication. IDK, I've just been told that are bodies start to resist anything that isn't "natural".
There are plenty of meds on the market that don't affect your libido, you might want to mention to your psychiatrist about a drug class called Mood Stabilzers. I can totally relate, I felt neutered for over 10yrs, until I moved over to that MS class of drugs.