Call an ambulance, go to the hospital, receive correct treatment and let your insurance deal with the payment. The hospital can also liaise with immigration regarding your visa 👌
and if you don’t then you still need an onward travel ticket if asked. They want to see that you are planning to leave the country within the visa/visa free timeframe
long term visa yes. Tourist visa or visa exempt or any short term visa it is required. You can be denied at check in at the airport if you can’t prove onward travel if asked. I’ve only been asked a couple of times in 16 years but it does happen and people are denied