@teaandcakewithdragons Think of those emotions that come with the Slough of Despond as a signal, a flashing light that's communicating information to you. A lot of times we interpret our subconscious frustration in quite bad faith -- that is, we subconsciously notice that something is wrong, we feel frustrated, the brain signals "Hello :) I'm frustrated" and this gets translated into the conscious mind as, "UGH!!!! This sucks and I hate it!"
First step to get through it is to take a breath and try to rewind. "This sucks and I hate it" is a signal. It's a signal. It's not the truth, it's just a signal. A little red flag that your brain is waving to say, "Hang on, something's off here." For me, the more I try to ignore the signal or talk myself out of it ("no, don't be silly, it's fine, you loved this last week") the more loud and insistent the signal gets until I CAN'T ignore it, and by that point I'm upset.
Here is the big secret: The opposite of anxiety isn't tranquility -- it's curiosity. If you want to beat the Slough of Desponds... Get curious. Stop trying to ignore the signals your brain is using to try to get you to pay attention to a problem. Stop as soon as you feel a signal, turn TOWARDS it instead of away from it, and think with loving curiosity, "Okay, what's going on here?" And then LISTEN to what you tell yourself with compassion and kindness--and curiosity, curiosity, curiosity.
If your brain is saying, "This is bad and I hate it," ask yourself: "Okay, good to know! What would I like more? What's the ideal outcome? What would be FUN?" Ask yourself, "Hmmm, what's bad about it? When did it start being ''''''bad'''''''? What is the source of the bad?" You will probably have to go back a few pages to figure it out -- usually between 5-20. Tap on the walls to figure out which one is hollow. Check the taps to see which one is dripping. Use the Rubber Ducky method that programmers know about -- get a rubber duckie (or a pet, or a very small child) and explain the problem in small enough words that a little rubber duckie could understand. Stay curious! If you can't figure it out, go have a shower, or a snack, or go for a drive, or sleep. Your brain will keep chewing on it. When you figure it out, you will KNOW, because your whole brain will light up like Christmas and you will feel a surge of delight and joy. "Oh! Of course! I forgot that she was supposed to be sad after her grandfather's funeral, so the vibes of this whole scene with her love interest are WAY OFF! No wonder I was feeling cranky! Hey, that's such an easy thing to fix, I'll just... [tinkers around in the scene, changes a few lines, tweaks the description, adds the poignancy of Grief] Oh that's SO much better!" <- Like that. That's how it will feel.
Another example of what your brain might say: "Ugh, why should I care, why should anyone care, what's the point", those are actually fantastic questions already! Yes! That is your brain telling you, "You know what, i think we need to make this MATTER more to the protagonist. We need to know why SHE cares. Why DOES she care? Why is this problem she's facing CRUCIALLY IMPORTANT, and what disaster will happen if she doesn't solve it?" If the main character doesn't have a reason to particularly care, neither does the reader, and neither do you, and since your brain is really smart, it already knows that. It is trying to help you. It's doing its job.
Listen to what your emotions are trying to tell you. Trust your gut. If the little cranky toddler of your brain tugs on your sleeve, give it your attention and ask it questions. It knows what is wrong and it will point it out to you if you pay attention. I cannot tell you how much easier writing got once I learned this skill. My god I have saved myself so much headache. These days, I do not hit the Slough of Desponds NEARLY so hard as I used to -- at worst I only dip a toe into it now and then. A few sighs and grumbles, sure, a little complaining in a friend's DMs, maybe setting the project aside to stew for a couple weeks and develop some depth of flavor... That's it. It has been YEARS since I had a "sobbing into a pillow that I'm a hack and I'll never amount to anything and everything I write is trash" kind of Slough of Desponds. Because I pay attention to the signals and I stop and do a systems check the moment something goes "BZZT!"