If a student is on the voyage of seeking knowledge, however, his sexual desires increases and he does not have the ability to marry in the country he is [seeking knowledge] in, should he return to his country, even though there are no students of knowledge there, and seeking knowledge is not as easy there as it is here?

Shaykh Muḥammad ibn Hādī al-Madkhalī:

We say to him: return to your country, marry, and protect your chastity, thereafter, return to your journey of seeking knowledge another time. This is because [marriage] is an obligation upon you now, and the regulation of marriage falls under five different rulings: obligatory, encouraged, prohibited, disliked, and normal/permissible. So it is obligatory upon you. The Prophet ﷺ said: “Whoever among you can afford it, let him get married, for it is more effective in lowering the gaze and guarding one’s chastity. And whoever cannot afford it, let him fast, for it will be a shield for him.” [Muslim, no. 1400].

Therefore, you are now in need, so you must lower your gaze and protect your chastity. If Allah ﷻ wills, you will accomplish what is to come after.