Digestive problems after moving to Japan

[KumaKuma]

I moved to Japan about a month ago and since I've arrived I've been experiencing persistent and intense stomach problems. I can't yet go to the doctor because my health card hasn't arrived yet. I have been eating pretty well, still including fiber in my diet and plenty of water. However, my stomach is in shambles. I have aches, pains, and I am feeling highly fatigued and dizzy a lot of the time. I have to eliminate a couple times a day, and it's always a painful experience. I'm getting muscle weakness, a sore throat, and nausea pretty frequently. My food doesn't seem to be digesting properly and it's not solid. I'm starting to get kind of worried...does anyone know what might be going on and how I can fix it?

[RadioKid]

If your "health card" is issued in Japan and sure to be issued, you can get tentative health card before your health card being issued.

When you can convince the doctor some how that the health card is surely issued within this month, doctor (or staff) will accept your card in advance.

Though I can say nothing about medical matters, I'm afraid you could have too mush meal and cold drinks. Warm green tea will be no harm and calm yourself.