Look on youtube for some guides on using the Sword and Shield if you haven't already. There are sometimes attacks that aren't listed in the guide or in the training area UI, so you may be missing out on some higher damaging attacks. In general with Sword and Shield though you are going to need to either match elemental weapons with specific monster weaknesses or use a status weapon like paralysis or sleep to be able to use bombs. Sleep bombing is a very popular playstyle. The weapon is also balanced around being able to use items and the slinger without sheathing, so try to find ways to use that to your advantage. SxS may do lower damage overall, but with a good bag of tricks you should have more free time attacking the monster than many other weapons.