You are doing the right thing by wrapping your head around it well before you submerge. You are getting good advice. Make sure you are at the point where the freaking out part is completed before you dive. Being concerned in an informed way and plans to actively address those concerns as need be firmly in place is the place to be (head space wise). You get there you will have it covered. All else (i.e. clueless w/o concern and hoping for the best or still freaking out) is sort of a bad idea uw.