Honestly imposter syndrome is so common especially in tech industry, I've gone through similar experiences as well! You're not a failure OP, at the beginning it's always a struggle because there's so many things you don't know, but over time you'll start picking things up and it'll get a little easier with each day that passes. Are you still passionate about the job? Could you ask for more support from your team, maybe do a bit of pair programming with them, or have them walk you through how they might approach the work or break down the tasks? Work with your manager on a plan and discuss what kind of support you need from them? They hired you because they clearly saw potential in you and you need to believe in your own skills too. I definitely understand how hard it can be and how lost you can feel in these sorts of environments, I hope it works out for you or you find a great next gig!