I originally live in India but currently I'm visiting Bangkok and though I did find some new Pokémons every time I get them in the Pokeball, they get out in the first try and run away. Neither am I able to get stuff from the poke stops. Will someone please tell me what is going on?
The issue you have encountered is called as Soft ban. You will not be able to catch pokemon neither be able to get items from pokestops. It happens if you travel long distance in short amount of time , it is included to prevent Pokemon sniping and GPS spoofing. Soft- Ban usually last for 1-3 days or may last up to 1 week depending on distance. So wait for some days you will be fine and don't use any hacks (GPS spoofs) to prevent it.