I grew up in the envirnoment you speak off, I knew as a kid I couldn't rely on my caregivers for any support, and that didn't change as I matured. As hurtful as it is, the truth is, I learn't to rely on no-one for support and I knew I could only rely on myself.
Over time, I have carefully and slowly learn't to trust a few very good friends and they have been able to understand and have gone along way to heal some of the gaps I had been carring around.
I think Elf, once you process and come to a place that you can let go of expecting emotional support from them, (in normal relationships, this is an entitlment), you will feel alot better about the being self relient for your validation. But the difficulty is, reaching that place can be painful, as you go through a process of grieving what you have never had but should have had all along