Re: "People will call you paranoid..."
If they do, then they have been made aware of your preparations.
And, if they know of your preparations, then your efforts are in vain, for those who laugh at you now will in time of disaster appear armed outside of your residence/shelter, demanding that you admit them and share your supplies with them.
So either "keep your plans to yourself", or be prepared to use your survival weapons to eliminate any and all wanting to avail themselves of your "food and shelter".
There is more to nuclear disaster planning than simply putting concrete over your head and having two weeks of food and water in reserve -- think about such things as human waste elimination and storage for two weeks (or more) in a small underground area, the danger of disease or sepsis from even small scratches or cuts, as well as how to survive after emerging from your shelter into an area with no electricity, no water, food, or fuel, and populated by roaming gangs and individuals who are sick, hungry, armed, and willing to kill for one matchstick.
Each and every "warning flag" has long been waving: "A prolonged period of international tension / domestic unrest and instability / 'saber rattling' between nations / etc. "
Those now unprepared to survive what's coming are running way behind in their planning. There will be very little time available to enter your fully prepared place of shelter once "an incident" takes place, so download the survival plans link I earlier posted for readers.
I would also strongly recommend researching "electro-magnetic pulse weapon [EMP]" and "surviving chemical or biological weapons", because our enemies are way more sophisticated in their planning than most of us are willing to admit.
Regardless of all else, the first rule of advice would be to leave the city and take up a new place of residence in a less populated rural area.
In my opinion, all of these steps are "easier said than done" -- all the more so as the collapsing economy increasingly limits our freedoms to travel and make purchases.
In my humble opinion, I still recommend immediate aliyah as our best option, for I believe that those who "stay and fight" will find that they can only fight to stay alive from day to day against almost impossible odds. Another thing to consider is that those of the "David Duke camp" will have the greatest odds of surviving such a disaster -- most of them live in less populated areas, they have long been preparing and storing supplies as well as weaponry, have "country boy" survival skills, and are more likely than others to emerge alive, well armed, and well organized.