I do get your concern - but I don't think it's rational. I mean that in a very positive way! I just don't think it's going to happen. Having chatted with thousands of lucid dreamers now, I've had only two say "I lucid dreamed for a week / a year". I draw two conclusions from this:
1. Statistically, it's irrational for you to fear this scenario. How many people claim to get stuck in a lucid dream for years? How many people claim to get stuck in regular dreams for years? Why are you worried about one and not the other? To fear this scenario, it's like worrying that an asteroid is going to strike you on the head and kill you, so you don't go out the house. Equally, an asteroid could land on your house. There's nothing you can do about it, even if it does happen (which is extremely unlikely).
2. Of the two people who made this claim, they didn't speak negatively of the experience. In fact, they were kind of proud of it. And like you, I sense it's just an elaborate dream-time distortion. (Nothing on the scale of Inception which, remember, was exaggerated for effect. It was a science fiction movie not based on reality, so we really can't draw any real life conclusions from it.)
Personally, I don't relate to "being stuck in a lucid dream for a lifetime" and I don't believe I ever will. I've lucid dreamed of a lifetime, sure, and it felt like it lasted ages in hindsight. But at no point did I feel stuck in the dream, or like I was going crazy, or that I would be trapped for years to come.
I would love to probe these claims further, but so far no-one has been able to properly explain it to me. Just because you dreamed you lived an entire life, does not mean you literally did, minute-for-minute, in your perception of the dream. I'm sorry this has created fear for you, because I do believe it's largely a myth. I welcome anyone who wants to share their personal experiences but as yet, the anecdotes and their explanations do seem very thin on the ground.