It has to be Misa from 9RIP and Kisa from JackJeanne for me. I feel like their struggles are really relatable because almost everyone has experienced that kind of anxiety about their future at least once in their life
Well, I rarely identify with a protagonist, at least not in personality, but as you say, right when they wonder about what they are going to do in their future and this spirit of moving forward and not giving up, I identified with Teuta from Bustafellows, although I also identified more with Mozu, we share similar professions and her insensitivity to life and death moved me quite a bit since I myself have felt it.
Ceres from Virche. My mental state used to be really bad — I often thought about ending my life — but she's so much stronger than I am. I think I might need to keep learning from her resilient spirit.