i cried for the first time in 7 years the other day. I think it just was all too much for me that day.
The illness situation you deal with regularly is extremely difficult. SI is a part of that--I have it too, all the damn time. There would be something wrong with you if you didn't cry sometimes. I wouldn't read too much into it. Stop judging yourself so harshly. You are a hero! What you fight? What you deal with? A damn hero!! My hero.
You have a bunch of people here on PC who do care about you, to whom it does matter very much, in fact, how you are feeling and doing. Don't forget that. I have almost no friends (okay, I have two) and no contact with my family of origin and precious little with my 'partner' and kids. I guess I am radioactive or something. But I have you guys and that's what helps me make it through.
Sending you self-compassion and strength and kindness to self. You will push through this. You will feel better. Maybe tomorrow after a bit f sleep.