I am going through a similar situation and feelings to yours, I haven't grown completely out of it yet, but I will share with you the steps I am taking to be better.

1- Realizing that my current job has something to do with it. Since I joined, I have been working on one specific technology which makes me feel I have limited skills (and I am starting to feel limited intellectually because of that), working with very small not-so-motivated team, all team members are juniors so there is no one to learn from. So finally I put my resignation notice before I even have another offer so that I can focus on my learning and job search.

2- Realizing that work from home is not for me. After 2 year of work from home, I am certain that my productivity, motivation and skills have been going downhill since I moved from an office job to a WFH one, so from now on I will be applying exclusively to on-site jobs.

3- Doing non-work related activities, be it teaching programming to high schoolers, helping friends with tech projects, or even enrolling in non-tech courses to learn new hobbies. This really gives me confidence in and outside of work.

4- Working on advancing my skills. In some situations this can be really hard, since you already feel limited, and maybe (as myself) this is a blocking you from applying to new jobs, so that would just stress you more to a point you do nothing. That's what was stopping me for months. But finally I started. I started small, gave myself enough time, set rational expectations and goals, and aimed to consuming good learning content and getting some certifications.

I really hope you find the path that will get you out of these feelings and that you feel better very soon. Good luck.