Dreams (nightmares) of nuclear explosions.. how I didn't die!

Two nights ago, I had a dream that I was in my home and a nuclear bomb went off on the horizon, The next moment I was swimming deeper and deeper into a lake or the sea and the water got very hot. I swam down to cooler water and eventually resurfaced to face a city which had been vaporised. Other bombs went off after this creating an extremely bright Violet light which I believe would happen in real life. The Blasts from these didn't reach me.

Firstly.. this is the second dream in as many weeks of nuclear bombs going off, the last one was launched nearby but turned around in the sky and hit us. I hope that this isn't one of those dreams that comes true

Secondly... would it actually be possible to survive the blast from a nuclear bomb underwater? How deep would you have to go because Im sure a lot of water would instantly be evaporated. I presume that if you are deep enough the temperature wont be so high?

Three major things will get you in the nuke blast.

1.The Blast force that equals 50% of a nukes energy, depending how close you are and what is between you and the blast will determined your survival.
For the 15 kiloton nuke dropped on Hiroshima The area of total vaporization from the atomic bomb blast measured one half mile in diameter; total destruction one mile in diameter; severe blast damage as much as two miles in diameter. Within a diameter of two and a half miles, everything flammable burned. The remaining area of the blast zone was riddled with serious blazes that stretched out to the final edge at a little over three miles in diameter.
Now we do have some around 5 megaton, but most of ours and the worlds nukes are 100k to 500k since the blast radius becomes increasingly harder to expand and so a 5 megaton bomb blast is only a few times bigger than a 100 kiloton hence the small nukes are more efficient.
A one megaton weapon would cause 105 square miles of 3+ psi destruction and 8 low tech 20 kilotons detonated in a circle would caused even more damage.

2. Fire Ball equals 35% of the nukes thermal energy. At Hiroshima, it has been estimated, solid materials on the ground immediately below the burst probably attained surface temperatures of 3,000 to 4,000°C (5,400 to 7,200°F)." And as far away as 0.61 mile, they may have reached 1,800°C (3,270°F). With a 250 Kt weapon such heat could readily extend from 1.1 to 2.6 miles; with 550 Kt it could be 2 to 3.9 miles. Thermal radiation from a nuclear explosion ignited upholstery and caused fire to spread in this car at the Nevada test site.

3. Gamma Radiation, this is where your water comes into play to save you. You need about 10 feet of water to prevent the gamma rays from passing through your body and killing cells. So, if you swim down and hold your breath a few mins and you’re outside the blast/fireball radius the water can save your life. But one other thing is you will then need to get indoors quickly for the fallout partials will continue to have gamma radiation and will continue to produce the radiation killing your cells if you do not have further protection between it and you.

I also dreamed about nuclear explosions. I saw one in the distance, then more right in front of my house at about 200 meters . I thought of running, but then I realized there is nowhere to run, even if I escape the bomb the radiation would kill me