Help -- the ending? (SPOILERS)

**** SPOILER ALERT ****

Can anyone help me please to understand the ending?

Marcel seems headed towards a tragic end -- his (ex) wife has more or less told him to get lost, he doesn't really know that his son is looking for him (and indeed, his son is shown looking for him to no avail at the shop), and Marcel has taken his gun with him. Then, in the dream-like sequence that ends the film, Marcel hands the gun to his country-singing idol, who makes a cameo appearance, and walks back towards Berlin (we can see the television tower in the distance).

I presume we are supposed to think that Marcel has considered suicide but thought better of it, and is going back to the shop where he will run into hsi son who is looking for him. But what is it that gives him that hope when everything in the plot is pointing in the other direction? Are we supposed to think that the dream meeting with the country singer means that Marcel has thought of the line in the song "My best friend is my father" and that encourages him to go back and look for his son?

This is driving me mad, can anyone help?

Thanks.