Some days, you've just got to make stuff even when you don't want to. I think this is the big difference that separates amateur and professional creative work.
Crucially, I'm adopting a distinction between 'professional' and 'amateur' which is not intended as a value judgement, but one that represents focus and key considerations. 'Professional', to me, means someone deriving a notable part of their income from the relevant work, who therefore have to bring some commercial considerations to how they go about it. That might be in terms of the actual output, e.g. 'this game needs to make money', or it can be about their direct relationship with the work, e.g. 'this is how I make my living; I need to produce work in a manner that supports that', or anything else along those lines.
(For me, it's both. I get paid for my work, and that matters to me, because that enables me to keep doing it. That was different as a freelancer than salaried in-house, but similar in each case. Many of the things I work on have their own commercial sensibilities which impact process and approach. There are things I work on that don't really conform to either of these; it's a range.)
A key difference to, say, writing for a living is that sometimes you just don't wanna. Or: your find your brain and/or body in a place that's not maximally conduicive to solving narrative problems or actually sitting down and getting down a bunch of words. This can be the case in any job. It's one of the reasons that I value structure and process so much (both narrative-specific, but also in how I work more generally): because they help me break things down into manageable chunks and push myself forward when I have to work 'uphill'.
(This is true in a different way of non-professional or not-for-hire work of course. I'm not suggesting that creative work is anything other than well, work, often hard. Doing it for yourself can sometimes be harder in that the lack of extrinsic pressure can make self-motivation more difficult. But the relationship between work and circumstances is, necessarily, different.)
When I find myself in this position, I'm grateful for being so structured -- that I think Narrative is process and process narrative, to refer back to a previous post. Or to have ways that remind me How to Write When You Can't.