The early modern period, encompassing the Renaissance and Reformation, was not one in which it was particularly difficult to survive. Although there were certain social and religious upheavals, not everyone was affected by them.
The greatest threat to survival in the late middle ages was the "Black Death" or "Great Plague", which may have killed up to half the population of Europe. By the Renaissance, the plague had run its course. Medical science was not as advanced as it is now, leading to high infant and maternal mortality rates, but people continued to reproduce and populations swiftly recovered from the plague.
The majority of people were poor, involved in agricultural labor, and fed themselves by growing their own food. The diet of the vast majority of people was primarily vegetarian, with occasional eggs or milk, with meat being a rare and special treat. In the absence of refrigeration, people often used root cellars to preserve food over the winter, although winter was a harsh time for poorer people given lack of fresh food and limited heating.
The wealthy had better food, including a meat-heavy diet, an ample supply of firewood and warm clothing, and did not have to do the manual labor involved in raising their own food. However, conditions were still harsh and, by modern standards, extremely dirty.