I had a similar problem when i reached lvl 20-25 because i could not find a legendary or exotic version of the gun i was using during the campaign (scout rifle). Then i had a lucky RNG drop with the last words and started to enjoy handcannons although i have never played with one before. There are three alternatives. First one you carry on with the game and start to level the first legendary / exotic primary weapon you get no matter which kind if weapon. Second one you start collecting reputation marks and points and save them for the faction gear. As far as i can remember the vanguard has a nice handcannon for 135-150 marks. Last but not least you try to do as many bounties a day and then take the exotic bounty for the thorn handcannon ;)