I never had a dog, but I have a cat who loves people. She showed mistrust to only one human, and that human ended up in prison a while later for abusing animals. I've trusted her judgement ever since.
I do research online before making big purchases, so whenever a salesman tries to upsell me, I ask them about the differences between the products, then make my own desicion of wether or not their points are valid. I've ended up with a more expensive product only once, and it turned out for the best.
If you make your trauma your whole personality, you will pull others down with you. Instead, learn from the trauma (what not to do) and try to become a better person. Speak openly about it when the topic is brought up, but don't focus on it. It will let your friends know you struggle at times, but are still capable of being fun, interresting, caring etc.
By showing your friends you are more than your trauma, it's easier for them to be there and support you on your bad days, because they see the potentional.
