Gravity Anxiety

I am not a scientist, but I sometimes speculate about what might happen if the laws of nature were to change. I've seen disaster movies that feature the sun cooking the earth or meteors crashing into the ocean and causing tidal waves, but I can think of a much scarier situation. I am talking about messing with gravity. I have thought of a couple scenarios that concern me.

The first one is gravity getting turned off. This would not be as fun as people think it would be. You would just kind of float around and stuff would be all over the place. On the positive side, you could probably still air swim or burp like in Charlie and the Chocolate Factory to navigate around. The next scenario is much more dangerous.

Gravity reversal. Can you imagine how bad it would be if gravity reversed and sucked everything that wasn't bolted down up into the sky? This would be like when you let go of a helium balloon outside. Animals, peoples, cars, dumpsters, boulders, and many homes would free fall upward into the sky. When gravity finally got reversed again, the earth's surface would be slammed with falling debris. People who were lucky enough to be inside would suffer broken necks or would be crushed by their water beds.

Yes, I really think about this stuff. I doubt this scenario will ever take place but I still worry about it enough to not jog in the dessert or in wide open spaces without telephone poles or trees near by.