Perhaps it's a medical thing, perhaps it's a living situation thing, perhaps it's a you just don't care about sex thing. Whatever it is, it will become a major source of unhappiness for both of you and will likely lead to resentment and bitterness on both ends. This will then be the end of your relationship.
Here's the reality, he will never not want to have sex on a regular basis, and you may or may not in the future be more into it. But doing it for his benefit is not going to make you happy, and eventually, he will get tired of having a partner who is not enthusiastic about it.
I see your options as thus:
Ask him to be patient until you can see a doctor. Hormone issues definitely affect the libido, and there may be something that can be done medically. If it's not hormones and you just have low libido, you will have to consider the other options.
Open your relationship so he can get his sexual needs fulfilled with other people, because if you never have sex, chances are he will cheat anyways if his libido remains at this level. Many couples can make polyamory work, but there is a lot of communication that has to occur first. If this option interests you, go and check out r/polyamory.
Couples therapy/sex therapy. Might help.
Last resort, but the two of you may just be sexually incompatible, which is something that may never change. A breakup would be better for both of you if you reach this conclusion so you can each find partners who are better matched.
Good luck.