Sadly that is how my first few cons went.... totally hyped myself up and hoping for something that never happened. :/
I can totally relate with this VN it was me several times at cons, painful and overwhelming it's easy to get carried away.
I have learned the hard way to go to cons with NO PLAN and just go with the flow! If it happens it happens, and I never get the "post con depression" cause I made the time I had there what I wanted and had a great time doing so with no planed agendas.
Best advise I give is DO NOT MAKE "plans" they only fail and flake out last minute, just go and have a great time!