I am currently missing a libido. Not sure what the reason is and the doctors are also stumped. No erections, no desire, no porn, nothin.

I'm 26, eat healthy/everything, lift, occasional cardio, had sex once in my life with an escort.

I currently take this multivitamin: http://www.hollandandbarrett.com/shop/product/holland-barrett-ultra-man-caplets-60031489

I have read to try some combination of: zinc, vit D, magnesium. Are the levels in this multivitamin sufficient or should I add an extra dosage of these 3 specifically?