Hi pretty nerd,
First and foremost get on your own team! You got through nursing school, you passed the NCLEX and earned your nursing degree. You are not dumb. But you do sound discouraged and isolated, so kudos to you for reaching out here.
Prep work: You Tube effective interview strategies and practice your answers in front of the mirror. Smile with eye contact, firm brief handshake and take your cues on level of formality from your interviewer. Try to line up a letter of recommendation and a few professional references if possible. Update your resume, as an alum you can reach out to career services at your school for help with this. Sometimes librarians at your public library may as well.
Since you feel insecure about your clinical skills look for a place that will help foster the fundamentals. I would recommend looking up the survey scores and reviews for long term care facilities in your area. They often really need staff and are nowhere near as picky about lack of experience as more acute facilities. If possible pick a small family owned place if there are any near you.
The patients in those facilities will all need their HTN, DM, CHF, CKD etc. managed and will teach you time management to get your med pass and treatments done. But you'll have time to learn your people and tasks because of the repetitive nature of LTC.
After a year or 2 of that you're good to go, SNF/rehab or home care whatever you want to do.
When I'm in a negative mental space I often look up TED talks relevant to my current issues, and I find them to be very comforting. Also cheaper than a therapist. Highly recommend walks in scenic outdoor spaces as another good way to get in a positive head space. You are enough.