Frustrated

My fiance never wants to have sex anymore and its beyond frustrating and depressing since we are supposed to be trying for a baby 💔 he says its not me cause hes attracted to me it's just hes never in the mood apparently...hes a little underweight could that affect things or could his testosterone be low idk I just want it fixed hes only 28 and I'm 21 I'm not ready for no sex at all I want a family