Is it easier to be a tall boxer than a short one?

I think your friend knows how to use his height and reach advantage. It would really be tough for you to beat him especially if he's skilled enough and a counterpuncher. Just like the Klitsko's nobody could beat em because of their size and reach advantage and they know how to utilize them. Try to do in and out and side to side movement like pacquiao. Work on your speed too. I'm not saying it would be easy to do all that. Bottomline is you have to force him to fight you inside not outside.