Husband always too tired to have sex

We have agreed that we will start TTC this month the proper way. But husband is always too tired or doesn't seem serious about it at all. I feel really sad. I know it may take people up to a year of trying and not succeeding to be considered infertile. We have been married 8 months and tried without tracking ovulation. Doctor gave us another 4 months before going in for detailed check ups, and from his semen analysis he's low in motility and morphology.. Why is he still not taking this seriously???