Hello. I'm 20 Years Old And I've Had My Period

Hello. I'm 20 years old and I've had my period twice this month. The first was the beginning, lasted two days and I had severe stomach pain and back. Went to the hospital for it and he didn't find much wrong, I wasn't pregnant. But he found a little bit of vaginitis. I've been doing quite a bit of coughing. And As of today, I started bleeding again like a period. With back pain and very severe abdominal pain. But now I'm feeling very weak and dizzy. Sometimes I'm so dizzy that I sometimes can't walk straight. I don't know what's going on, and i would love some input.