Left pain under rib cage.

So I started having this pain for about 2 weeks, It got to a point to where it was hurting super bad I had to rush to the E.R I would sneeze and it was literally a super sharp pain, I would cough and the same thing, they did x-rays and they said it was a U.T.I and some muscle was swollen due to the infection. They only gave me 800 mg ibuprofen and sent me home but the pain is getting so much worse now. I'm trying so hard to avoid the E.R. I can't make a appointment with a primary doctor because my insurance card hasn't came in the mail. I keep looking online to see if it's anything else but nothing really comes up. 😔 Do any of you have a idea as what it could be? I doubt it's a U.T.I I pee perfectly fine no pain at all. I stretch and it hurts so bad should I go back in and have them check again? I'm in so much pain. just need some opinions as what it could be.