Lately i've had a number of dreams of similar themes - the end of the world scenario, and also a couple in which everyone, or just myself, was preparing to die.

The end of the world. I had a couple about this scenario.
In the one i can remember, i was one of a handful of survivors, and the dream was mainly concerning our interactions. Whether we decided to band together and help one another, or to fight against each other.
I don't remember too much of the actual detail and story now - it was last week sometime, but one point i do remember, is that i met a woman, who wanted to try to procreate with me, but i wouldn't, until i'd made sure my gf wasn't actually alive somewhere...
Could loyalty/sentimentality get in the way of the continuation of the human race?

Preparing to die. I had one where everyone was going to die soon. They all knew it. They were allowed to die in whatever way they saw fit. People were living out their fantasies before their time was up.
Some chose to commit sexual acts with strangers. Others went skydiving. Some made peace with friends they'd lost. Others simply jumped off of tall buildings.

In another, which was later in the same night, i was preparing for my own death.
I found my oldest friend, and my girlfriend.
We all held hands in a circle. I told them how glad i was that they were with me at this time.
We lay down on a huge bean-bag, as i started to weep with happiness.
I felt the strength drain from my physical body, and my breath become shallow.
The breaths became shorter and shorter, and i became still, at peace. Perfectly still. No thoughts, no concerns. Just stillness, and then light.