I literally have no one that cares about me...how can I care about myself?

I’ve suffered from depression since the 4th grade. That was brought on by my fathers remarriage to a woman that kept him away from my brother and I.
I’ve had suicidal tendencies. In all I think I’ve attempted suicide at least 5 times but I think about it everyday.

I’ve tried to think of people who really care about me and I came up with two friends from school but even they’re iffy because one is a new friend and the other has ditched me for other people several times and doesn’t even feel bad about it.

I feel like my father must care about me a little but when my stepmom harasses me he just goes along with it.
A lot of the “caring” received from either of them I feel is usually fake.
For instance I just had a conversation with them an hour ago and we talked civilly and then I left and came into the hallway to get a picture of my cat (I’m a photographer, not a weirdo) and I heard my parents literally bashing everything I had just said to them and criticizing me as a person calling me a liar and selfish, etc.
So I walked in and said I could hear them and they acted like they didn’t say anything.
What hurts is that my dad knows he was just talking about me and that it hurt my feelings and he hasn’t apologized.
It probably hasn’t even crossed his mind that he probably should apologize.

My mother only cares about herself and money. I’ve tried talking to her before about my feelings and life and she kept diverting the conversation to how I should sue my father for money and how there’s unequal treatment between my brother and I and that I’m spoiled.
She’s mentally ill. She doesn’t live in reality…she’s created her own and it’s difficult to have a relationship with her.
My siblings are the same considering they were raised by her.

I don’t want to go into too much detail about how my parents treat me because this could get really long.
The problem is I’m bullied and manipulated at home by my stepmother and then at school I’m just ignored.
I’ve been going to this school for four years and maybe 10 people know my name. I do talk to people, they just forget me within a week.

I feel pretty worthless almost every day and I wonder what the point of even living is if no one cares about my feelings or acknowledges my existence.

How can I learn to love myself when no one loves me?
It seems when I build myself up even a little someone tears me down without fail.

(I’m not going to kill myself I just sometimes question the point of my life…I’m adding that because I don’t want this to get deleted just because I’m depressed. I legitimately want to know how I can repair my self esteem when I’m surrounded by people who can’t stand me)