I wait until the flower spike turns yellow/brown & dried out before I
cut it off. Then I know it's not going to make more flowers on the
same stem. I have 2 kinds of fertilizer, the first being an ordinary
Schultz regular-plant fertilizer, which was all I had for ages here in
the middle of nowhere, & they did fine with it... & the 2nd is a
Schultz orchid fertilizer which is supposed to encourage bloom. This
is probably pretty amateur, but if it starts making a new leaf after it
blooms, I fertilize with the regular stuff for a while, then the orchid
stuff after the leaf gets to be a good size. Often they will make a
leaf or 2, then another spike, but I have had some start new spikes
right away before the old one has turned completely brown. I figure
that means they have enough leaves & are just ready to bloom again. So
it might not take 6 months for yours to rebloom.
I don't fertilize every time; you can get a buildup of salts from too
much fertilizer.
As well as good light, I am under the impression phals also need a
temperature drop at night to bloom, although not as fussy as some
orchids. So if yours is on a windowsill that gets cooler at night,
that might help too.
The more experienced growers here can probably give you more scientific
advice than me & set any of my errors right too.
Yes, they are addictive. I started with "just one" some years ago, &
now have 16 orchids; the only reason I don't have more is that I
literally have no more windowsill space. The last remaining spot
belongs to the kitty
Good luck with it.

Alison