I was farming some blood echoes by killing everything in one area then I continued and went on until I passed 2 areas. Then I fell from height by accident and I was spawned at first area. I wanted my echoes and there was a long distance between me and my echoes.
If I enter hunter's dream and travel to nearest lantern to my echoes, does this make them disappear?
No, Blood Echoes don't disappear if you fast-travel. In fact, it's even recommended to use it if you for some reason cannot find them (source):
If you have looked everywhere for your Blood Echoes and cannot find them either where you lost them, or in the Lecture Building, try going to the Hunter's dream and then back to the place you lost them. You should now be able to find either your blood stain, or an enemy which has absorbed them.
