Trust the process: it sounds very ideal and it's probably overused, but in reality it holds so much truth.
From time to time I'll share on a #penanadpaintsketch how my creative process can be a struggle. I really want to share those feelings of inadequacy with other creatives. I want them to know they are not the only ones who feel their work isn't good enough. I want them to know it takes time and lots of mistakes. I want them to know even through mistakes beautiful things can be created. Every time I take time to open up I am encouraged by others and I see a wonderful dialog open up. Yesterday when I posted this someone commented, "But it's also about letting yourself make stuff you hate! It's just a piece of paper... Not the end of the world (though it can 100% feel like it)." Talk about perspective. It's just a piece of paper. You can start over again. You can trust the process and push through, and something magical will happen. You can finish what you started and hate it, but at least you did it.
I hope you are also learning to trust the process, no matter what it is.