If you were somehow able to fall at terminal velocity forever, assuming you are in a stable environment without any external factors that would affect your fall, there are a few factors to consider regarding your survival and eventual demise:
Terminal Velocity: Terminal velocity is the maximum velocity an object can reach while falling through a fluid, such as air. It occurs when the force of gravity pulling the object downward is balanced by the upward drag force of the fluid. For a human body in freefall, terminal velocity typically ranges from about 53 to 56 meters per second (120 to 125 miles per hour).
Oxygen and Atmospheric Conditions: As you continuously fall through the atmosphere, you would be subject to the available oxygen supply at that altitude. Eventually, you would reach a point where the oxygen levels would be insufficient to sustain your body's vital functions. The exact altitude at which this occurs depends on various factors, including the individual's physical condition and the altitude where the oxygen concentration becomes critical.
Physical Health and Survival Skills: Assuming you have an unlimited supply of oxygen and are in perfect health, your ability to survive the fall would still be limited by your need for sustenance, hydration, and protection from extreme temperatures. Without access to food, water, and shelter, your survival time would be relatively short, even if the fall itself is sustained indefinitely.
Impact and Trauma: Even if you managed to overcome the previous challenges, falling at terminal velocity for an extended period would eventually expose your body to immense physical stress and trauma. Continuous impact with the air molecules at high speeds could result in severe injuries, internal damage, and ultimately, death.
Considering these factors, it is difficult to provide an exact timeframe for survival in this hypothetical scenario. However, without essential resources for survival and the inevitable physical trauma resulting from continuous freefall, it is unlikely that a person could survive for an extended period under such conditions.