Bearded dragon euthanization?

So. Listen to this thouraghly. Not half assly. So I have a bearded dragon and he is my son pretty much. But he has yellow fungus, and it's horribly bad. I mean horrible. He only has two legs, from stuck shed and an accident with other babies when he was a baby. He only has a couple toes and fingers. But I love him. No doubt. He's my child. But.. He needs to be put down.. (crying while typing). And I'm poor. Is there anyway I could do it, humanly, and painless? I was thinking about getting about 10 fireflys, blending them, and feeding it to him through a syringe. But I dunno if that's painful. Please don't rag on me. Please. This is already hard on me, and if I had the money. I'd take him to get it done by a vet. But I have none.. No job either.