Question: How can I cope with loneliness? From the noumenal perspective, all hungers are for the eternal, hence the seeking of refuge in Pure Land. It is the day-to-day grind from the phenomenal perspective that causes difficulty. Mindfulness of Buddha (Nianfo practice) is the panacea for all suffering, but when alone, and not doing Nianfo, problems arise.
Answer: The answer is already in the last line of your question. Nianfo is still the swiftest and most ready cure. (Deeper study of the Pure Land teachings can also further inspire your Nianfo practice.) The moment there is any form of suffering, be it loneliness or any other difficulty, it is exactly when Nianfo should all the more be practised. Suffering is but a reminder to (re)align to our Buddha-nature via more sincere Nianfo, which will alleviate suffering, and even give rise to bliss due to connection with Amituofo’s (Amitabha Buddha) blessings.
Bear in mind too, that all suffering arise from the Three Poisons of greed, hatred and delusion. The suffering of loneliness is actually a subtle form of greed for company. The best of company is always to be one with our Buddha-nature and the blessings of Buddha experienced from Nianfo, which later becomes the physical company of ‘all such beings of superior goodness’（诸上善人）in Pure Land.
With deep Faith that this spiritual company, even if just in the mind for now is indeed pure and ideal, one will not keep craving for worldly company, that might be impure and lust-filled. This is how good practitioners easily find peaceful joy, even in solitude. It is not that all relationships are frowned upon, but there is no need to deliberately crave for new relationships, which might lead to suffering when disappointed, and even hamper sincere Nianfo due to distracting attachment.
There is also no perfect worldly relationship possible here. Constant pining for perfect friendship or love is thus self-sabotage, that has been causing us to be stuck in the rounds of rebirth. What should be done is to deepen and purify all existing and naturally arising new relationships, to be more spiritually intimate with ourselves, so as to connect one another to Amituofo as much as possible, to ‘meet together in [the] one place’（俱会一处）that is Pure Land later. This is the purest form of love.