what always helped me was I would say in my head " Huck it of F*** it, I didnt come all this way to chicken out and not hit anything " a good thing to also di is try to find the speed your comferatable with and ride up to the jump at that speed then at the last second pull on your brake, thus stopping before the jump. do this a couple of times untill your comferatable.
hitting the jump: alright you are going to want to hit the speed that your cool with and just go off the jump, make sure not to squeeze your brake in the air or that'll throw you foreward. make sure when you goo off, to keep your front wheel up till you see your landing, when you see your landing then just nose into it. keep 1-2 fingers on your brake lever just incase its a wierd landing
the first couple of times you might case it, but that happens to all of us.
ride with a buddy or make sure people are around so if you fall and get F***** up, there will be somewhare there