Help! Picky eater!

I need ideas/suggestions on how to get my axolotl onto a sustainable diet. I've had him for nearly 3 weeks now. He's a little over a year old, 8 inches. The chick I got him from only fed him bloodworms. I know this is not a sustainable food source. I've been attempting to get him on earthworms but he refuses. I feed him about every other day. I use tongs. I fed him bloodworms the first 2-3 times while he was adjusting to his new tank. Then decided to try him on earthworms.
At first I gave him a smaller earthworm whole and he sucked it up and then spit it out. Then I read that some axolotls don't like the taste of the slime worms excrete so the next time I fed him, I ran a worm under hot water for a second to kill it, then cold water to rinse away any bitter taste, then cut it into smaller pieces. He ate one tiny bit and then refused to eat the rest of it.
I waited 4 days in between feeding him thinking maybe if he's hungry enough, he'll eat. Nope.
I've now resorted to putting a few bloodworms on the tongs with a piece of earthworm. It's working.... kind of. He's catching on to the trick and now refusing to eat that too.
I'm worried he's too skinny and might not be getting the nutrients he needs.
Thanks in advance for any help!

What kind of earthworms are you trying? If you can, get your hands on some nightcrawlers (or if you have friends who are avid fishers they may be able to lend some) and give them a go. In my experience axies find them irresistible. You will probably need to cut them up into pieces the width of the axolotls head.

This is exactly the right time of year for buying night crawlers, find places in your area that sell fishing tackle, give them a call and ask if they have live bait, if they do there's probably a fridge full of nightcrawlers. They will probably be huge, but i hope to one day be as excited about anything as my axolotls get about them.

You could also try blanching any worms, my little guy was pretty picky about that. Nightcrawlers produce a clear mucus that, while not as strong as red wigglers, is pretty gross to touch and makes them hard to manage. Cutting them up and then blanching them has worked well for me.

Other than that, just take it slow. You could probably try mixing some pellets in to his diet too, mine loves the hikari sinking carnivore pellets more than anything else, which surprised me!