Extremely Underfed Python. HELP?

[kippers]

I bought a young ball python on Craigslist just three days ago and noticed that he had somewhat loose skin and maybe two or three bumps that looked like sores. I asked around and was directed to a local pet store dedicated to exotic animals and they said the "sores" were probably just bits of his last shed and that he was extremely underfed. He had been eating pretty small white mice, once a week up until I got him. I bought two medium size mice and he ate them both that day, but I'm worried that they still may not be big enough and that maybe the double feeding could stress him out. What size mouse/rat should I be feeding him and how many per feeding until he grows to his proper size?
1. How long have you had your ball python?
3 days, the guy I bought him from had him for 2 weeks and I believe directly from a pet store. I'm assuming the store has some blame in this as well as misinforming the new owners.

2. How old (or how big) is your snake?
He is a young snake and looks to be maybe about 2 ft give or take a few inches.

3. Does it eat on a regular schedule?
He was eating a small white mouse, maybe 2 steps up from a pinky (not quite sure) but he was eating every friday, though I was advised to feed him the 2 medium sized mice on Monday. And he did eat them.

4. How long since its last meal?
2 days

5. What type/size prey is being offered?
A medium size brown mouse

6. How often do you offer food?
The schedule for my corn snake is every saturday and I was hoping to get my ball python on the same schedule.

7. What type and size of enclosure does it live in?
He inhabits a 10 gallon tank currently, and I am looking to get him into something a bit bigger.

8. What are you using as substrate? If it has depth, how deep is it?
Aspen bedding, approx. 3 1/2 inches worth.

9. What type of heating do you use?
A lamp, I think he has a 70 watt nocturnal bulb and his tank was 82*F when I checked last night. He has a heating pad as well but I haven't used it yet.

10. Do you use a thermostat to control temperatures?
No

11. What do you use to measure/monitor temperatures?
One temperature / humidity gauge under the lamp.

12. What are the surface and ambient temperatures in the enclosure?
13. What is the average humidity level?
14. How many and what type of hides does the snake have?
The rock hide he was purchased with he could not even get inside it was too small. I took a medium sized plastic bowl and made him a new hide that he uses and it is on the warm side of the tank.

15. Is water readily available at all times?
Yes

16. Does the snake live alone or does it share the enclosure with anything else?
He is alone

17. How often and for how long is the snake typically handled?
I have handled him briefly each day, anywhere between 5-15 minutes, from his previous owners I don't know how often they handled him.

18. Does the snake have any medical history (old injuries or illnesses)?
None that I'm aware of.

19. Do you have any other reptiles? Have you brought in any new reptiles recently?
I have a cornsnake with no problems that I bought from Petco ( I know, I know, don't hate) 3 weeks ago.

20. Is there anything specific or unique about your situation that we should be aware of?
I am not the most informed about sizes of the mice, am new to the ball python, but have done quite a bit of research and am ready to properly care for this animal.

[Rickys_Reptiles]

I've never been a huge fan of feeding mice, so my advise would be switch to rats.

Without knowing his weight, I'm not sure if you should feed weaned or small rats. Could you weigh him and advise?

[OctagonGecko729]

Black out three sides of his 10 gallon tank with construction paper taped to the sides for more security.

Stop handling him for now.

Add another hide on the cool side for him to feel more secure.

Upload us a picture of him on the ground next to a dollar bill if you do not have a gram scale to weigh him.

It sounds like he will be ok because he is still eating but pictures and/or a weight would help us help you a lot.

The temperatures should be bumped up as well but we can deal with that after the pictures. Do not plug in the heatpad without a thermostat or rheostat attached to it.

[kippers]

Now I don't have super accurate scales, but he is about a pound.
EDIT: His temp is now 90 but his humidity is low, at 33 for sure. Will post pictures in a moment.

[Rickys_Reptiles]

Now I don't have super accurate scales, but he is about a pound.

Well, lets put it this way. I feed my Ball Pythons that are around 300 grams small rats.

[bcr229]

Now I don't have super accurate scales, but he is about a pound.

WalMart kitchen section has digital gram scales for about $20.

EDIT: His temp is now 90 but his humidity is low, at 33 for sure. Will post pictures in a moment.

Is that 90*F ambient, or is it measured with an IR thermometer on the top of the substrate at the hot spot? If ambient that's high, but fine for the hot spot.

[kippers]

Hope this helps a bit.

[kippers]

The humidity/ thermometer gauge is stuck to the inside of the tank on the warm side, but about halfway between the top and bottom of the cage. I can move it I'm sure.

EDIT: Now I feel incredibly stupid, but with limited knowledge of what each size looks like, I googled "small rat" and this looks exactly like what I just fed him. So I will change that info above, and forgive my ignorance. Im a beginner.

[Rickys_Reptiles]

Hope this helps a bit.

small rats for sure (50-100g)

[kippers]

Knowing that small rats should be fed to smaller pythons than mine, he was still being underfed when I did feed him. Size wise anyway since he did eat two. Any advice on how to adjust his meals safely?
Also, is he in as bad a shape as I was told?