Swapping a torsion spring yourself is the one repair we'll talk you out of. That spring is holding a door's full weight under tension, and even on the lighter doors common in a 1989-built Seffner house, the bars used to wind it can snap back hard enough to break bones. Things you can safely check first: the sensor eyes near the floor on each track, which just need realigning if the door reverses before closing; the track bolts, which loosen over time and are a simple tighten; and the weatherstripping along the bottom, which dries out in this climate faster than the mechanical parts do. If the door won't move at all, or you see a gap in the spring coil above the door, stop there and call it in. We're coming from Brandon, about 5 miles out, so it's not an instant fix, but it beats a trip to the ER.