Awww, how terribly sad. But please try not to be too dispirited for too long. I know it's very disappointing and very upsetting when you have to open your eggs to see tiny dead chicks, but if you stop trying now, that will always be your last memory of incubating. If you try to figure out what went wrong, and sort it out for the next time, you're very likely to end up with much happier memories and some cute little fuzzybutts to spoil. And look at it this way - it's a VERY steep learning curve and after just one incubation you know maybe 50 times as much as you did three weeks ago.
I suspect your problem was a combination of too low temperature and too high humidity, both of which are easily adjusted. I suggest you read a bit about still air bators, get the right temperature sorted out (I think 101.5F but not 100% certain) and drop your initial humidity to around 35%. If you want to be certain about what humidity is correct, you can weigh your eggs to determine moisture loss. It's easy, and VERY accurate. Candle and weigh at days 6 and 12, and adjust humidity as required. And maybe have a look around for the incubation 'cheat sheet' written by ChooksChick specially for still air bators. It's highly regarded by loads of people on here who have followed her recommendations with great success.
And I'll say it again, try not to feel too bad about your first attempt.
Most of the successful hatchers on here have got a string of horror stories they can tell about hatches that went wrong.