I know exactly how you feel mate, a couple of years ago my beardie died (the first beardie and reptile i'd ever owned), and i was still a kid at the time - didn't know enough about reptiles and what not. My beardie died from hind-leg-extention paralysis and it took about a week for him to die, was the sadest thing i've ever had to go through. I contacted an ex-melbourne zoo vet, i contact numerous reptile friends,took him to 3 vets, and in the end even got hold of some form of reptile oral steroids and what not off a highly knowledgable vet (friend of a friend) and just as i thought he might have had a miracle turn around he passed away. I did absolutely EVERYTHING to try save him - was pretty heart breaking but boy did i learn my lesson.
On the bright side, i learnt so much and just read everything and anything to figure out why, and after a while i got the confidence up to get another one and he is one of the healthiest beardies i've ever seen!
It's not hard to get attached to beardies with their wonderful characters.
Sorry for your loss.