Thank you for your post and I'm sorry you haven't had much luck with job searching. I totally hear your frustration and feeling defeated at not making it to the interview stage.
Having applied for lots of jobs before, I do understand how emotionally exhausting it can be to put all of your effort into an application only to have it either rejected or ignored. But it's important to know that this is never ever a reflection on you.
One reason why you might not be getting to the interview stage is because of your cover letter or resume; not being because it's wrong in anyway, but because wording can make all the difference. Employers flip through them so so quickly so all the little details (like short cover letters or fancy resumes) can make all the difference. Can I ask if you've ever considered contacting the employer? Sometimes it can come down to the sheer detail or perhaps there is feedback that they can provide.
While this idea might be a little daunting, I've done this before and it can be really helpful - especially if the jobs you are looking for and applying for are similar.
Hopefully this could be something to try. I know how defeating it is but I encourage you not to give up. There will be a job out there for you :)