Despite landing senior roles and so on, I suffer regularly from "imposter syndrome" - I think most people do to a certain degree. It's not unusual, it's sobering - but also good to challenge yourself. I think even the world's best experts need support from people. Life gets challenging, and sometimes it's easy to give up, but actually the sense of accomplishment when you've "beaten" something is really rewarding.
You just need to find a way around the wall.
Life is full of forks, and dead ends, but life does go on, so it's just knowing your way back to the fork in the road from a dead end and give it another go. Also making sure you learn from things is important.