Tony was giving up on life. He was ready to die after being dumped on the bunker in Siberia by Rogers. Nobody cared about him. But he didn't die. He woke up three days later to a crying Peter. Maybe somebody actually cared about him he thought, and slowly he realised how important Peter was and promised to not give up. Promise to live for Peter, for his kid. I have written the same story on my ao3 account so feel free to read it there too. DISCLAIMER I dont own Marvel or any of the characters.