I feel almost the same all the time, and I only have half of your exp. (professionally)
But it's always been like this, since I started development as a child in the 90ies. You don't know how this thing works, but you need it for you to success. There's simply no other valid solution at the moment. So you sit down, investigate, spend hours, sometimes days. You think about throwing in the towel, sit back, reflect your thoughts, try again.
And then, finally, things work. It's such a relief. And every time you get to this last step, you already became an expert in whatever you were doing.

I'd say it's like this for most people, but fewest have the guts to admit it. So thanks for sharing your thoughts!