New here … not sure if I am

6 months I started a new relationship with a married man. He left his wife and two teenage children to start a life with me.

It has been a rollercoaster of emotions and uncertainty. I want to be there to support him but I feel I’ve lost myself in everything that has happened, which results to fallings out, arguments, anxiety. I am very person who is very insecure about myself not had the most supportive past relationships, but he is different completely different he wants to be there for me and would not hurt me in the ways I have before. But I still keep messing up, I still don’t understand how I should be.