I can certainly relate. I also create/design things for a living and of boy do I get the same feelings every single time I create something.
It’s an emotional rollercoaster where everything from self-loathing to “damn I’m good at this!” feelings come and go. I’ve just accepted that it’s the way it goes. The way the process works I guess.
It scares me sometimes how much the creative state of mind can change. Sometimes I can create a number of cool things in a relatively short time. Then there are those times when I really struggle to get a single creative thing done. Completely drawing a blank.
But I guess what always drives me back is the process itself. Even though it’s hard, it’s also highly rewarding (well, usually!). I do it for the love for the process, “the grind” so to speak. I cannot think of myself stopping doing this. No matter what.