First I want to say that I'm over twice your age, so my (similar) experience was from the early to mid 90s...but it's not different from what you're going through now, so I understand the frustration and disillusionment you're feeling and I'm sorry you're feeling those emotions. But please please don't think you will never be hired anywhere. It seems like, for different reasons over the decades, finding employment has always generally been a challenge unless you're either 1) friends/know someone who can get or give you a job; or 2) just very lucky or in the right place at the right time. I remember my friend who at 25 had gotten his masters degree from NYU and STILL couldn't get hired ANYWHERE in our town or other cities -- and he was every day sending out countless resumes, applying for jobs in person in our town...just doing everything he could. We tried to joke around about how many rejection letters and calls he used to get (or, no response at all) just to keep from crying about how discouraging it was. Both he and I took janitorial jobs during this time just to have SOME kind of income, but a part-time job like that for him (not for me, I had some college but never got a degree so I was just grateful for the office cleaning job) he was definitely overqualified for it and wanting something in the field he went to school for - but it just wasn't happening for him at that moment. He *did* eventually though get a wonderful and fulfilling career in his field, in a bigger city where he is now very happy and doing well and has a very good income. Those early-mid 20s years can be so hard for a lot of reasons, not lastly the employment factor, and I apparently that doesn't/hasn't changed much since I was your age decades ago. I guess this is my longwinded way of trying to reassure you that you are NOT unemployable, and that while what you're experiencing sucks and takes a toll on a person in a lot of ways, don't let your own mind - or anyone else - convince you it means you aren't employable or that you won't ever find work. You will. <3 Just try to have patience (hard, I know), trust that in time it WILL happen (harder yet, I know), and persistence to keep jobseeking and applying (VERY hard, I know. the continual rejection wears down your confidence and your hope and you get very very tired of trying and getting nowhere and you wonder "What's wrong with me? What's the point of filling out ANOTHER application or submitting ANOTHER resume?" But...it's all you can do unfortunately. And it WILL all eventually pay off.)
In the meanwhile, while it wouldn't be work you went to school for or be 'fulfilling' (for many people), if you took a job like what my friend and I did (office cleaning) it'll at least be some income, another reference, will show you're wanting and willing to work, and will make you feel you're at least doing SOMETHING. Plus, speaking for myself, at that age, it could be hard physical work depending on the type of work you're doing and therefore I found it to be a daily workout that I got paid for. I actually enjoyed cleaning -- I just vaccummed and dusted, others emptied trash, or did floors, etc. I assume things in janitorial haven't changed THAT much since I did it over 20 yrs ago. And nobody was with me, I worked alone and listened to music. Low stress (unless you get an asshole boss). I definitely preferred it over a job that involved customers or working with the public. And especially in your case, a cleaning job, while many look down on it as 'menial' or 'lowly' - which is unfair and snobby and I get that people want jobs that are in their fields of study and so a cleaning/janitorial job, for them, would feel beneath their abilities and skills, it's still work and imo, any honest work is nothing to feel ashamed nor does it makes you a 'lesser' that anyone else, in ANY way - a job like that for you would only be temporary. Because you DO have higher education and you're actively seeking employment in your field of choice and a career position. These days though, there are lots more opportunities for work-from-home jobs that might interest you more than an office cleaning job, and maybe something like that would be better, I don't know. I just know I was happy with my cleaning work and being on my own, no boss around (usually) and it was physical work to a degree and that was good for me as well. So I wanted to toss that out as an option to consider while you seek a job or position that is more in line with your education and what you're really like to do in life.
Just please don't let this job search situation make you think you're employable or that it's a reflection on you personally, because I can pretty much guarantee that's NOT the case, even though I don't even know you. What you're going through and feeling right now is miserable but it's not going to always be this way. Please please take that from an old lady who clearly remembers going through this herself, as well as my highly educated best friend who went through the same thing during the same time as I.
Oh one last thing I wanted to mention -- I don't know where you live but I am in the US and in my state and town we had a "Job services office" where you could go to talk to job placement counselors, look at posted job listings (this was all before the internet became what it was and folks had to rely on bulletin boards and postings and listings vs online job searching) and take job placement testing, etc, that sort of thing. They would help people and jobs "hook up" so to speak. For some people, that was a great resource and very very helpful. Nowadays I'm sure most of it'd be online both just because INTERNET but also Covid, but maybe there is some kind of similar office that could help you?
Take heart and don't give up. You are NOT unemployable, even if it feels that way. Hugs and good luck to you <3