https://www.youtube.com/watch?v=BpeDcTv4aPM
I'm unsure whether you follow Rooster Teeth, but one their founders used to do a vlog and he did one on motivation - the topic starts around 4:39. Summarising he states:
Motivation isn't something that exists. And it isn't something that can be cultivated because it is an emotional component of inspiration.Motivation is fickle, you have to cultivate discipline in order to get stuff done. Motivation isn't something that you can force or get, it's something that comes to you on it's own volition.
And by cultivating discipline, working on things when you don't want to - that is how you can get things done over a long period of time and that is so much more reliable than the emotional component of motivation.
The trick is how to work without motivation.
It sounds like you have had a hard week and had a lot of things on your plate and therefore getting back into the groove is an issue.
Burnie mentions above one his tools he uses is streaks (taken from Jerry Seinfeld). Whatever he wants done - practicing, writing, etc. he has to do it everyday to keep the streak so when he is tempted to break it, he has X amount previously (10 days, 20days, 50days) and to break that streak is difficult because it's now become routine.
Thomas Frank (another YTer) found a way that putting money down will motivate you. I find it's part of a sunk cost fallacy mindset. Thomas wanted to become a morning person so he set up a programme on his alarm that 10 minutes after his alarm went off a tweet will send saying 'if you reply to this tweet I'll give you $10' so that was his incentive to wake up and prevent the tweet from being sent. I think he set that up and one or two people actually got $10 from him before it really pushed him to wake up on time. I state it's a sunk cost fallacy as when I started my gym membership, I felt that parting ways as a poor student made me want the most of my membership so I started going to the gym first thing in the morning.
So essentially it is about discipline.
Lastly I understand that the grind is sometimes too monotonous or difficult to continue. I've been learning Japanese for a long time and I got to the point where I was copying from a textbook without really taking anything in. It just became routine to copy and I went from learning 70% of the content to closer to 10% which meant re-reading and re-practicing. I was no longer enjoying learning the language as it was just routine I did (like watching TV or playing a game). So I switched it up. I looked for why I wanted to learn the language which was to actually read untranslated manga. So I found some raw scans of a series and started doing the translation with a dictionary and phrase book. I'm enjoying it immensely as I learn new vocab through repetition, and I'm rewarded as well allowing me to understand the story with each line.
It's a lot to read so apologies for the rambling post but I wish you all the best for your content creation