Every now and then a hot streak fizzles out and you're left walking past your paint table where the same four or five figures sit, collecting dust. You may even be tidying up and notice that stack of RPGs you were excited to read hasn't moved except for an idle flip through every now and then. A lot of times this happens because other, more-pressing, things in life demand your attention, but it can just as easily happen for no discernible reason at all. Every day at work, I see gamers and hobbyists and what they're working on comes up in idle chit-chat. Every so often I get the response that nothing is being worked on at all. "I just haven't been that motivated."
This is normal. It sometimes feels like you're admitting a shameful fact about your work ethic, when in reality sometimes this stuff comes and goes. Sometimes it's tied to a project, like when you're done, you take a break as you do other things. Sometimes (as in my case presently) it just happens in the middle of a project. For myself, I tend to have two things going on at any given time. This isn't always ideal, but sometimes I want to just pick at one set of figures, while really working on another. The same happens with RPGs. I have one book I'm reading that I've just bought, one I'm reading because I'm playing it currently, and/or one I'm reading because I want to run it the next time it's my turn to run games.
Miniatures-wise, I've been working on Myari's Purifiers from Warhammer Underworlds: Direchasm for what seems like ever, then decided to finish up some half-done Americans for Flames of War. Recently, with the stress of working retail during the pandemic, I've come home and just read some White Dwarfs I'm behind on, or a novel, before milling about the house doing chores. What seemed like one or two days without sitting down at the paint table, has turned into a habit of just passing it by while I head for the couch for an hour of brainless lounging. It's normal.
But let's say that your third day (or week) of passing by that stack of books, bunch of models, or even empty notebook that should contain an adventure or game, is starting to get to you. Maybe the urge is there but the motivation isn't. You could actually just wait around for the motivation to come back (it will), but that might take a while, and there are other things you can do in the meantime.
The first thing that needs to be done is you need to make time. I have an awful habit of mindlessly scrolling Twitter, and I've taken to getting up from the computer if I find myself refreshing the timeline for some hot takes, and grabbing a book. I did my scroll to see the latest in what gamers have to say about games; it's time to change to something more interactive (and frankly, productive).
You also need to clean your hobby, or reading, or writing, area. This often involves moving the stuff that's built up on and around the area and maybe organizing your paints, or cleaning your palettes. Right now, my ceramic palette is good to go, but my wet palette and water pots need changing. I could also do with putting some errant paint pots back in their drawers and only keeping out the ones pertinent to the project. Tidy that stack of books, put your pens in their pen... Holders... Put RPGs back on the shelf that you thought you'd get to, but don't need to right now. They're adding to the stack, and making the whole thing seem daunting.
As an addendum to that last point, it helps if you have a permanent home for your hobby. I have my paint station out, so all I have to do is sit down, turn on the light, and start working. Same with reading or writing. I have an area that's comfortable, well-lit, and has whatever I'm working on nearby in a neat stack. If you have to pull out your projects every time, I can see the motivation being dampened somewhat. Maybe try and think about a couple things that you think would make the process easier for you. Sorry I don't have more advice on that front. I've always been lucky enough to have space for my painting (even if it's about two feet square).
Finally, you actually need to sit down and fiddle with the stuff in front of you. Don't know if you really feel like painting? Just turn on the light and pick up a model. See what you were doing with it before you stopped and maybe take a fresh look at the colors or the process. Maybe you feel you can't concentrate on reading that RPG module that you were keen on a week ago. Just sit down and flip through it. Look at a map, or read an NPC's background. You'd be surprised what questions pop up and how that motivates you to keep going. Don't feel you need to dedicate a whole afternoon, or even a full hour to these activities. Sometimes you don't have that long, but any time at all will put it back into your brain that this activity can become part of your routine again.
You can also try alternating the aspects of your hobby. If you don't feel like painting, maybe looking at some paint guides, videos, or re-reading some parts of a codex or battletome might inspire you. At the very least you're still remaining connected to the hobby. The same goes for RPGs; if you can't be bothered to write something, just flip through a bestiary, or part of a rulebook you normally skip over (for me it's usually magic weapons and skill lists I skip when I'm reading a new RPG).
I guess what I'm getting at is that you shouldn't be too concerned with the lack of motivation that comes and goes, and that there are ways of tricking your brain, and coaxing it back into the a healthy hobby routine. For myself, I picked up an RPG module I'd like to run and started reading it last night, and today I'm hoping to pick up those Lumineth that have been sitting in their precarious paint handles for weeks and slapping on the first highlight to the red. I'll probably only do one coat, but at least that's something.