"Just an average person with no real explanation as to why they always feel a bit meh?"
There will be an explanation, you just haven't found it yet.
It could be a physical thing - an undiagnosed illness, dietary deficiency, menopause, sleep apnoea or disturbed sleep, long covid, etc.
It could be a lifestyle thing - lack of sleep hours, poor diet, lack of exercise, too much screen time, work stress, etc.
It could be a mental health thing - relationship issues, screen addiction, depression, lack of friends, not enough time in nature, etc.
You don't have to live like this. Keep looking and trying various changes.
However, you may find the cause(s) is something you are not willing or (yet) able to change, e.g. if is is caused by the wrong job, the wrong husband, wrong parents, or not wanting to be a mum of child(ren) of the age/stage they are at. Then you have to weigh up your options.