In some similar woriking circuit around the net, I see Power transistor being used instead of the Mosfet. Since the Mosfet is Either off Or on, but transistor can be inbetween, delivering say Half power, I am guessing Replacing Mosfet with transistor might work, what do you think?
As for the problem with physics, I don't think so. In videos of some levitation I seen, the object is kept stable right from the start. But in my case, it just starts wobbling around and then shoots out, even I carefully keep it in the right place. May be, my electromagnet isn't good?