how can i help myself when i constantly feel like i deserve to never get better to atone for my past mistakes

hi, i'm sorry for making this post, i hope it's ok. my entire life i've struggled with fitting anywhere, or being anywhere. i don't have a good relationship with my family and have been bullied to the point of being hurt by classmates and teachers and unable to even attend highschool because of it. due to birth complications i have several diagnosed mental disabilities and disorders and i was extremely unstable as a child.

the only friends i had for the longest time when i was a teenager also went through their own traumatic experiences but none of the relationships were healthy at all. finally at age 20 i've been trying to get my life together and make friends that are much more healthy to be around but i keep hurting people. i get into arguments so much irl with family that the pent up frustration i feel, sometimes i say things about my friends i really shouldn't be. and i get so distraught over the past that i air out all my emotions when none of them are prepared for it and it worries them so much.

i feel so bad. i was such a terrible friend. i've felt like a burden to people my entire life because anywhere i go i end up making things worse and hurting people i've cared about. i made so many mistakes when i was younger when i lacked any real sense of empathy at the time. i'm trying my best to learn it now but it's so stressful.

i feel like i don't deserve any good things to happen to me. that i've made this life for myself and for the sake of old friends i've hurt i deserve to not seek out care and waste resources on myself. i've been talking with more people recently and they call me their friend and i get so scared. i'm so terrified of hurting anyone ever again. i want to be a good friend and i want to be a good person but i'm so terrified it's too late. i feel like the only thing i'm good at in life is hurting people i care about so much.

i really want to try to be a better person, if not for myself at least for the friends i still have and whichever new friends i make too. i want to be positive and a fun person to be around but it's so difficult to when i'm stuck in a loop of feeling like i deserve to never be happy because i've made too many mistakes to count in my life