I'm not going to get into a K&M vs Controller argument but RPGs like this tend to be better suited to the former and games like Jedi Survivor etc. the latter. It's just an unfortunate truth because of just the depth of options, add in that Larian has never had good UI/Item management and the problem just becomes even more apparent.
I'm sorry I can't suggest anything for the OP but just know you're not alone but if you do get a chance to play the game on PC you'll find item management a little less frustrating, just a little :P
