Here's what worked for me. Your mileage may vary.
Volunteering. I picked a cause that I felt passionate about and learned to function in an environment where there were group goals that were not money oriented but community oriented. We all deeply cared about the same thing and I learned I could depend on other people and be patient and work through problems positively. Additionally because I chose a domestic violence org I learned about abuse, abuse cycles and the affects of abuse in a holistic manner. I learned to approach domestic violence and drug use in an objective, educational way which helped me with pattern analysis and avoiding pitfalls, cycles, etc.
Reading. I've done quite a bit of reading on what affects me. I didn't put too much faith into being 'diagnosed' with PTSD but just to see things through I tried to educate myself about it as much as possible. While I don't like to think of myself with a syndrome, I have to admit that it's entirely possible and probably. So, knowledge is power and whatnot.
Inspirational stories. It's a hard, lonely road to overcome abuse, addiction, family dysfunction. I've found I like survival stories. I needed to believe I didn't have to become what the statistics said I probably would, so I looked for inspirational examples.
'Healthy' examples. I know I didn't have them for parents so I looked to friends' parents or just people I had come to know. I've found that people that I assumed had a perfect life or an easy life often times didn't. They've had some serious low points or came from dysfunctional families themselves.
Common sense and instincts. I was raised with four basic emotions: fear, sadness, sense of loss, anger. I knew I had more and I explored them once I was out on my own and had the option to do so. Say please, thank you, show respect, share, follow the Golden Rule. Treat others the way you would like to be treated. Unless they're unhealthy creeps that want to hurt you. Then you give them the cold shoulder.
Believe... believe it can be done.
We are all here because we come from a line of survivors from our early ancestors to now. Througout millenia they've faced predators, disease, wars, famine, violent crime, political upheaval. Remember that you're from that line of survivors even though the generation or two before you might not have been so great, you have the ability to change that. I couldn't do much about it as a frightened five year old, but I'm a lot bigger now and a whole lot tougher.