Breast Hurts

Hi everyone! I need your help!! I am exclusively pumping and I pump usually every 2 and a half hours or maximum every 3 hours. Except at night that I may pump 5 hours after my last session. So the problem is tha a few days ago my right breast got really hard and it hurt a lot. I tried hot baths and hand expressing, pumping every 2 hours, warm compress and the next day was fine. Last night it started again. And I tried everything but nothing is happening.

To add, this breast does not flow when pumping, only a few drops. But when hand expressing is fine. My pump is new so I don't think that is anything wrong with it. What can I do? Thank you everyone and sorry if my English is bad! 😊