Hello Suze,
I sympathise with your anxieties, as I find myself in much the same position, even though I left university many years ago. I think it is normal to worry about these things and sometimes even be depressed by them. I remember very well how dark many of those months and years at university were (I ended up doing three university degrees, so I had many, many years of university!). However, I just picked myself up and did something, which might have worked out in the end, even though I was increasingly frustrated, until last year, when my mother died under my care and my husband announced the end of our marriage one month later. One of the many effects of these events has been to bring me back to a position which I lived through once as an undergraduate: what am I going to do with myself, will I be alone for the rest of my life, what is the meaning or point of my life? The problem for me, though, is that I am no longer a bright 22-year-old! I don't know if it is relevant for you, but I still honestly believe that we can do whatever we want, if we want it enough, and that includes changing our minds! I hope that you can find a way for yourself that will give you a sense of having accomplished something. Sometimes, that is enough.