Can you end a personal letter as is German with "Dein", for example: "Your Daniel"
I'm looking forward to your answers!
Yes you can, but in English it is extremely romantic and loving to do so; "Your Peter" means something like "Your everlasting and eternal true love, Peter." It can't really be compared to the Italian-Renaissance-inspired closings like "Vostro schiavo", "Votre humble serviteur", "Your most faithful servant." These are now defunct in English, essentially.
There's also "Your friend", "Your son", "Your daughter", and so on.