It is doubtful that you are going to convince your DM, but maybe you can convince the other players instead. Provide them with Crawford's tweet indicating that rogues are supposed to get Sneak Attack most of the time. See if they will all discuss the issue with the DM as a group (nicely), because they want the Rogue in their group and hope he'll change his mind. If he won't then change characters, and consider changing DMs or becoming a DM yourself --- you seem to read the rules better than he does.

Crawford's Tweet
https://mobile.twitter.com/jeremyecr...56159387656193