It's not so much the picking of a career or speciality that's frustrating or upsetting. My thinking on that domain is to do whatever is at the intersection of interesting, remunerative, and doesn't foreclose on too many future options. What ails me is how I tend to outsource my self-esteem to external factors, such as the attention of girls. I'm restive.
I don't have the inner peace that I see lots of older people have. It's like that peace is inextricably bound up in age and experience.