Your story had a deep emotional component to it and I liked that. The plot was one everyone can relate to: the devastation resulting from the loss of a loved one. Yet it felt rushed to me and I wanted to see some time taken to unpack some of Marty's experiences since the emotional aspects are so important to this story.

For example, his meeting Courtney and their bonding definitely feels too condensed. How do they get along in the bar? You talk about crying: what are they crying about? Does he talk about losing his mother, and has she lost someone? Since she dies of cancer later, it would seem likely that she has also lost a family member to cancer since some cancers have a genetic component. Does Marty talk about his alcoholic father, and does she understand that? You mention she helps him get clean and go to rehab: does she have an experience with addiction, or know others who have gone through it?

A bit minor, but the antiques dealer seems to give in a bit too quickly to Marty's demands. Why doesn't he try to barter up from ten percent?

I liked the ending of his daughter appearing and Marty calling his father for help. But why would he reach out to his father after all these years? I don't think you set up Marty's forgiveness of his father (I'm assuming he's forgiven him). I also agree that there should be a couple clues dropped as to the daughter's existence. Perhaps a flashback to a conversation Marty and Grace have about wanting children? Also, does Marty consider himself a failed father? Does he fear becoming like his father?

Also, how does Grace know he's sober enough to have his daughter back? Recovery is a slow process, and the time frame seems to imply that Grace gives him his daughter back the same day he decides not to sell the watch. If Grace cares about the girl, it is a bit unbelievable that she would think he was ready for taking care of his daughter again.

Finally, who is Grace? Why is she doing all this for him? She is a hell of a friend to go through this: giving him money, watching his daughter, stocking his fridge, etc. She needs a backstory, some sort of explanation. As it stands, she just seems to be there to make the plot work.

As noted elsewhere, the formatting of the paragraphs made it hard to read, and this could have used a proofreader. There were missing apostrophes, periods instead of question marks, spelling errors, missing words, etc. I saw you mentioned you weren't a native English speaker, so I understand it can be a challenge to catch all that yourself. I hope you can find someone to look over your stories for mechanical errors; it's a shame that such minor stuff can detract from a good story. :)