Nostalrius Begins - Quality wow vanilla realm (1.12)

well, my pc is pretty bad since its way too old, but i dont know why if i used to play normally WoWWotlk, i cant play classic normally. It always has bugged visuals and the screen torns up a lot but i already have at minimum settings and everything but it still is thrash and the frame rate is horrendous, i cant also click stuff when a try to loot a mob or acces my own inventory. I'll leave a pic of how it looks like to me



How do i fix this pls i want to play and also sorry for bad english

Search the forum"quality and smoothness"..sorry I forgot the title of this topic
.this topic shows settings to maximize quality and performance.^^

Here's the link: viewtopic.php?f=32&t=1100&hilit=quality+and+smoothness