How do I improve performance?

Hi all, I've recently have started stuttering and lagging in this game. I love this game even tho my Duelist is doggy poo at the moment. Is there a method to reduce graphics? I have everything low in-game. I'm also trying to use the defrag tool but I'm lost on how to actually use it... are there any other solutions?

Thanks a lot, guys, I hope we can meet each other in-game and be friends.(since I don't have any.) ヽ( ´▽)ノ