cannot get my load order to go where i want it to

hi guys, i'm using a tried and tested modlist by someone else, all the mods are downloaded but i just cannot get them in the right order? i've spent 2 hours trying to get them right but whenever i close the game/go out of the creations menu/even go out of the load order menu they just jump around into whatever order they like. it's so painful D: does anyone have any tips to prevent this?