Whatever meaning your dream has is personal to your views on life. Personallt I wouldn't be thrilled about seeing my world go into flames and fade away either. If you hold religious views in waking life and the concept of hell scares you, then this probably "was" hell for you. REM sleep (where you dream) has a natural increase in heartrate which can produce a variety of effects on your emotions. Now the difference to this heart rate increase in waking life is that you might attach the emotions based on the scenario you are subconsciously creating, whereas you would be presented with the stimuli from the external environment -> hear rate increase in waking life. So you could say that in your dreams you attach the cause to the effect you are already experiencing.

Besides that lucidity is always (and especially the first couple) a powerful experience and it can be frightening. The fact that you yourself refer to Constantine could be that that would be your interpretation of how it would look like if your world was coming to and end (in this case this is exactly what happened as your "current" world was in fact ceasing to exist because you were about to wake up), and I think that may be the only meaning you should attach to it =).

Now besides this it is normal to struggle with dream control and stabilisation during your first lucid (Hell I still struggle sometimes, especially when attempting to WILD), the way my dreams destabilise is normally a fade in vividness or I feel like I am being pulled out of my surroundings. Keep at it mate, now you know a bit more about what to expect from your body for your next lucids and I promise you the fear will fade with time.

I will congratulate you on your first lucid and advise you not to read too much into the way it ended =). If you have a hidden fear lucidity will be the best way of overcoming it ^^. Besides that, it took me nearly 40 lucids before I could set my surroundings on fire, whereas you seemed to nail it on the first attempt. Recognise what happened and practise controling it

Best of luck with your journey and welcome to the world of lucid dreaming =)