Happiest, if you are in danger then go NOW and don’t think about it. Call Hatzolah and go, they will give you the support you need. If you are 18 and over they will NOT tell your parents what the issue is if you ask them not to tell. They will tell you what the local Rabbonim paskened on whether you can return on Shabbos or not. In my neighborhood, Hatzolah has an account with a local car service so people can come go home. They give a card to the patients and the hospital calls for them.
Happiest, please don’t wait till Shabbos begins. Just know although the complications because of chill Shabbos just makes the anxiety worse. If you are not capable of getting the issue under control and feel that you should be in a hospital let Hatzolah take you otherwise you will be sitting in the emergency room forever and a day. Refuah Sheleimah