My dad had an neighbor call at 10 am if he had not called, after he moved away from family. I guess you could even offer to pay a small fee or a gift card for the service.
Having the Apple Watch helps me to feel secure about what would happen if i were alone and passed out or had a heart attack or stroke, because the watch will call emergency phone numbers for me if i fall and do not respond. Since you are not in the US, I am not sure if that would even help you in Mexico; but if it did, then some kind of an alarm that you can wear would at least be of some help. I think that all states have facilities for low income seniors, and you might want to consider moving back to the US where you could have help nearby if you need it, and someone who would be willing to check in on you. There are low income apartments as well as senior care facilities, so you would be able to have whichever level of help you feel that you need. Even if you have to leave a lot behind in order to move, the peace of mind and better safety would be worth doing it, in my opinion.
The only suggestion I have is to leave Mexico and move back to the USA and semi assisted living. I can't imagine living in Mexico or anywhere and having no friends and no one to look after you.