Oh dear! All I can say is that we are dealing with wave-particles and wave-particles are not like particles, because of the additional rules imposed on their behaviour by their wave-like nature! The wave equation only has certain solutions, corresponding to standing wave patterns, and nothing else is possible. So the electron can only have certain energies, none of which is as low as it would be if it fell into the nucleus. Paradoxically, you can have an excited state of the hydrogen atom, with the electron in, say, the 2s orbital, with no angular momentum because l=0, yet it can emit a photon and drop down to a lower energy state, say 1p, in the process gaining a unit of angular momentum (l=1)! This serves to illustrate how the "orbiting electron" Rutherford-Bohr model of the atom does not work, as we discussed in an earlier thread. I'd be happy if any other reader has a more satisfying way to visualise what is going on, but the way I've always seen it, this is just why we need "wave" or "quantum" mechanics.