Vets unable to diagnose my puppy. Please help.

UPDATE: My baby is slowly and miraculously recovering. Although we can't know for sure, the vet seems to think she had some sort of meningitis. Thank you all.

I’m hoping that someone here can shed some light on what’s going on with my 3-month-old puppy. My local vets have been unable to diagnose her condition. I am currently living in Sri Lanka. My husband and I adopted a stray puppy (mother gave birth in our yard) about two months ago. Our little Nova is a mutt and I think she has a bit of Pomeranian in her (I’m not too good with identifying different breeds; I’ll post a photo). We have not given her any vaccines yet as she just turned 3 months old on July 2nd.

On the night of July 1st, she started having seizures. She would chomp her jaw, salivate (frothy), sometimes her body would stiffen into a very slight bridge shape (like an upside-down U). At first the seizures were very far apart (between 2 and 5 hours I would say). We rushed her to our local veterinary hospital as soon as it opened that morning. Unfortunately, there is no overnight emergency care where we live.

(Video of her seizures - https://youtu.be/9nWII0YSe7A , this was July 2nd morning, video title is wrong)
Two vets and a couple of vet techs saw her and they all agreed that she did not look like she had rabies at all. She was friendly, eating, and drinking. They prescribed an antacid syrup (for any toxic materials that might be in her GI tract) and these two drugs twice per day: sodium valproate and simethicone. For the first dose (morning of July 2nd) we administered all 3 meds together as we did not know that the syrup could inhibit absorption of the drugs. For the second dose, we gave Nova the syrup 2 hours before giving the two pills (pills were given right before having her dinner). She ate a fair amount that night although she did not have her usual ravenous appetite.

Overnight, her seizures became much more frequent (all in the same manner initially described), and a few times she ran around the room aimlessly, sometimes bumping into furniture. She would also try to scratch her head with the ground. I noticed that picking her up or putting her down (when going outside) sometimes triggered the seizures. But other times, they just happened seemingly on their own, whether she was asleep or awake. She had about 25 seizures that night.

We rushed her to the hospital as soon as it opened again. The trajectory was about 30 minutes of a windy road and stop and go traffic. She seemed to have a nonstop seizure through the entire trip. The vets were then entertaining the possibility that it could be an unusual case of rabies (among many other more probable diagnosis). They gave her saline and sedated her with (diazepam or xylazine, can't remember which). Her jaw became locked and we could not administer any oral medications. She was placed in solitary confinement at the veterinary hospital and my husband and I went to the human hospital to start the rabies vaccination schedule on ourselves as we have been in contact with her saliva and we have scratches and small cuts on our hands.

Here is what has transpired since then:

July 3rd

4 PM – She was drenched in her own saliva and urine. There was also some diarrhea in her confinement pen. She was sedated, given glucose, saline, and atropine for the salivation. Jaw clenched shut. Her ears hung forward limply (but not much differently as they usually do, she just wasn't able to move them). Tail was not stiff. Not aggressive but startled by loud noises and wanting to move around the table at times. Seizures were now tremors/trembling on the sides of the mouth and head slowly oscillating from side to side, unable to focus on anything. We took as much precaution as possible when handling her (spraying alcohol, using gloves, etc.), still considering the minor possibility of rabies.

5 PM – She was given saline, glucose, and atropine. Little to no change in symptoms. Pupils were lethargic but not unusual in size. We left her overnight in solitary confinement.

July 4th (Video: https://youtu.be/8ZOx7u8S4OM)

8 AM - There was very slight improvement, no new symptoms. A tiny bit less shaking/oscillating of the head. A little more responsive to us. Not aggressive. She might have been tired or a coincidence, but she responded to the “sit” command twice. Jaw still clenched shut. We were denied a G-tube for pill medications as the head vet deemed it too big of a risk (in case it is rabies). At this point, unable to properly diagnose her condition, the vet wanted to experiment with different drugs. She was given saline, glucose, sedated, and given the following:
Candid ear drops - 2 each ear
Methyl Prednisolone - (central nervous system inflammation and trauma protocol)
atropine
diazepam
ranitidine
vit B complex

4 PM
Slight improvement. Little to no tremor in jaw. Walked around a bit. Jaw mostly locked.
Given:
2nd dose of Methyl Prednisolone
glucose
saline
atropine

July 5th

9 AM
Again, very slight improvement. We left a container with food the night before (plain yogurt and corned beef from a can) and water in her pen. It seems like she ate maybe half or a third of the food. Water container was empty. Less tremors on the side of the mouth. Less head oscillation.
Given:
saline
glucose

(My husband is currently with her, unsure of what other medicines they will try to administer this morning, will update post later)

Note:
1. They've also been treating her with metronidazole as well, but I'm unsure of when exactly. These last few days have been a haze for me.

2. Three weeks ago we took her to a private vet due to drops of blood in her feces. Feces was a lot softer than usual. She was given an antibiotic.

3. (June 20th, 2018) 3 Days after the above mentioned vet visit we returned for a checkup. Her temp was 103, and the vet noticed that her trachea was enlarged. He prescribed: agmentine 200mg twice per day, Dexamethasone 2.5 mg twice per day, Piriton 2mg twice per day.

4. We started house breaking her about 2 weeks ago. She spent half of her time in her kennel (taken outside every 1 to 3 hours). And half of her time free roaming a room in the house, supervised.

5. We live next to a small wooded area where there are monkeys, bats, snakes, snails, frogs, and god knows what else. I've supervised Nova every time but she still chewed on things on the ground once in a while.

Please give me any advice or insight you can offer. Thank you in advance.