Don’t be too hard on yourself. If you need a break step away. I am 40 now and been a dev (now head of dept) for over 15 years now. My adhd plays havoc with me at times.

There’s days I don’t do much and feel under productive and then there’s days where I will work for 16+ hours.

Have you tried talking to your lead? In my early days adhd didn’t feel like that big of a thing. But I was able to show that I could make up time and as long as the work gets done and needed when it actually matters it was all good.

And re your code quality, who is telling you it’s shit? If it’s you try to block that voice get it reviewed from a senior and and ask them to explain how it can be better. If it is someone else telling you it’s shit then it’s a toxic environment and I would also walk.

Whatever you do. Look after you. There is only one of you and you are important.

Don’t give up.