is there something I can download that increases my FPS like fastcraft and that doesn't crash me every two seconds...? and is updated
As long as it does not end in .jar it should not be detected as a valid mod, and thus not loaded by forge. You can rename it fastcraft.dis, fastcraft.jar.dis, fastcraft.jar_dis or anything you like, as long as it is as said, not pure fastcraft.jar
You could also try updating fastcraft to the latest version. It's usually more stable than optifine with mods.
