Only you know the answer to this one. Even though I’m generally a proponent of regular, consistent writing for those who have the urge to write more, there are an infinite number of ways that writing happens. The question is – are you happy enough with your current state of writing affairs?
If you only put pen to paper once a year, but create something you truly value, whose to say you should write more than that? Many famous writers have experienced long droughts in their productivity, brought on by various life circumstances, illness or alcohol abuse. Whose to say that their writing lives should have happened any other way? It is hard to sustain consistent writing practice over the years, and many issues, internal and external, conspire to undermine our best laid plans.
Still, like so many skills, if you stay engaged with writing practice, you tend to get better and generate new ideas, and this is less likely if you avoid writing for long periods of time. In addition, if you deny yourself the many potential gratificationsthat come from writing, you may be a less happy person than you’d like to be.
Most writers I work with feel uneasy when they aren’t writing for long periods of time. Some of them also feel uneasy when they are writing regularly, but at least they know that uneasiness isn’t about not writing. If you are someone who is blessed or cursed with the urge to write and you aren’t doing it, you suffer.