The more good relationships you have in your life the more secure you will Becone.
The more insecure relationships you've got the more you can be pushed into some of the 3 insecure attachment patterns and then you can find it difficult to get healthy relationships afterwards.
What good relationships do you have in your life now ?What is good in your life now ?.
Then write down the relationships that have been challenging. Write what was good. Then write down what you would have wanted that had been more of in the challenging relationship and feel it in your body.
What would you have whished had happened. Your old part of the brain does not know the difference between past and present. It believes that everything is happening right now. If you feel it in your body, your brain thinks it is the reality.