Hello! I'm three days late with my period and it's very painful, not …

Hello! I'm three days late with my period and it's very painful, not like usual. It's been four days now, they're almost over, but I'm really worried about back pain, constant nausea, fatigue, I feel exhausted all the time, I go to the bathroom every 10 minutes, literally, and can't sleep because of that. Has anyone experienced this? What should I do? Can I drink any herbal teas? What is this even called? I've never had anything like this before, could it be an infection? I'm in another city and only see a doctor at the end of August.