wow such good ideas and replies, I'll start by adding my experiences then maybe some advice.
Time, time, time is the big killer when it comes to anything, if you have very little free time then trying to squeeze anything into a restricted time space
can be annoying and perhaps leaves you impatient. I speak for myself here.
Other than that as some have said, motivation can be results orientated and losing especially can remove motivation.
What I do in these situations is watch some tv poker, then choose some small mtt/
freerolls , and simply try to make a few deep runs,
once I manage that, then back into my usual games.
Also I would advise change of
poker games, NL PLO PLO8 Big-0 and all these variants, can spice up the motivation.
.
note - I've noticed that this possibly doesn't apply to cash games, let me get better at cash games and add another post then
good luck and enjoy