The dream seems to be about career fears, perhaps about being able to support yourself since the focus is on your leg. Spiders represent irrational fears and the color of the tarantula (orange, black) ties these fears to career. Even though the dream is scary and it seems being injured is a bad sign, you really can relax. An irrational fear means exactly how it's stated. You are afraid over nothing or, you don't need to be afraid. Usually when something is coming "towards you" it's indicating that this will be happening in the near future. Something that will make you want to freak out. Don't worry though, your fears will not manifest. They are completely irrational. :) Do you have any idea already what this might be related to?