Sadly, denial is a part of the disorder of anorexia. It took me years to realize what was going on with me. Even my family bought into the denial.
It sounds like you’ve looked at the rational, objective facts-you are underweight and losing, you have symptoms of malnourishment, you are hungry, tired, and irritable, and you are fixated on weight and calories-and gotten an answer.
It sounds like your heart, or your intuition, or whatever you want to call the less data-based part of you, is giving you a similar answer as to what is “wrong” with you.
And it sounds like the answer you are getting from both sources-objective, and subjective-is the same.
Do you live in a decently-sized city? Can you try to see a therapist, preferably one who knows about eating disorders/anorexia athletica in men? I think you would find it tremendously helpful. This is so hard to do alone. You could also look into support groups.