I'd like to think it's not beyond hope but he is in rough shape. Even though Leo's are hardy little guys babies are fragile.
It's great that he ate a bit and is drinking. All you can really do for him is offer food and water and hope for the best. 30 celsius is a bit cool still, can you boost it up a bit on one end (33 c)? He could do with a warmer spot I think.
I do hope he comes around for you and pulls through.
Do you have herp vets where you are? Maybe get a fecal float done, he may be carrying a large parasite load too.