Katty,
Your in a tough position.
Blood pythons are not the easiest snake to keep being a beginner (i still have problems every once in a while.)
Also, chances are, seeing that the guy said he cant sex em at that age, which is ridiculous as well as the fact that you are located close to there native land I would guess its probably not Captive Bred, which means it may have multiple types of internal and/or external parasites.
Something that should be checked by a qualified herp vet.
your temperatures are a bit tricky as well.
If you cant find a cooler room, say in the 78-81 F (26C) degree range i would leave your baby blood at your room temperature.
I have been talking with a few blood keepers in the US, and we have concluded that bloods shouldn't be kept as warm as most ppl have been told to keep them at.
i have found that with hot spots of 90 degree F (32C) dont really get used much. I have switched to 80F (26C) ambient, and 86F(30C) hot spot for babies. For my adults i have done the same and since then, i have seen much more thermoregulation.
Now assuming you cant get the temps any cooler and you are positive those are the correct temps of the enclosure, if i was in your position, i would keep your baby just with your ambient room temp. Many large scale blood breeders keep all there babies in room temp of 86 degrees. And although the best thing to have is a heat gradient, 85-86 degrees ambient with a 90 hot spot would sure make me feel worried about my snake getting a respiratory infection as there isn't much of a cooler place to move too.
Keeping your snake like this temporary shouldn't have any ill effects. but as it grows, i would consider either finding somewhere to house it where you can give it the proper heat gradient or find a new home for it, and possibly look into some sort of desert species of lizard or something else that requires high temperatures.
Im not too knowledgeable on Asian seasons...
Is it these temps year round, or is this the cooler or warmer part of the year?
If this is the hottest it gets there in your part of asia, i would say you could adequately house it like that for the hotter months with just ambient temps, then switch to using a undertank heater on one side for the cooler months. However, this, is just an option, not the most ideal way to keep a blood python.
And yes, my website is not up at the moment, but heres a link to an "in need of an update" caresheet which you can check out right here on ssnakess.com.
Caresheet Link
Hope this has helped,
Grant vg