When do you draw the line between self-care and self-love in hard times?
I'm presuming that self-love in this question means inappropriate self-love, in other words selfishness.
Self-care is a cute and precious term I prefer to avoid. To care for a child or animal is usually concomitant with a degree of pity, affection, and sentimentality. Brushing one's teeth, having a bath, and eating broccoli are not pitying, affectionate, or sentimental acts, either by nature or by association. Self-care is really taking care of the basics so I can get on with my life adequately.
Absolute prerequisites are sufficient untroubled sleep, a very good diet, and plenty of exercise. The practice of one's own programme (Steps Ten through Twelve, and, if one is in the first nine Steps, those Steps, too) also falls within this category. The management and administration of one's own affairs is a further element.
Once these basic necessities are met, a certain amount of the day can be given over to the fulfilment of responsibilities, whether work, service, family, household, or other.
The allocation of time between these I find to be a function of the circumstances at the time. One must ask God and then allocate the time reasonably, according to the urgency and seriousness of the needs in question, amongst many other factors, disregarding personal comfort and preference unless all other factors are equal.
The ability to draw the line stems from the application of the above principles, experience, detachment, impartiality, equanimity, and the complete dropping of demands for praise, recognition, comfort or other ego commodities.
Regarding the last element of the question about hard times: the answer in hard times is the same as the answer in easy times, although one regularly has to extend oneself further. What 'gives', however, is pure leisure time, not the above maintenance (= self-care) time.