Hello ? I already have established lactation and everything was fine: I…

Hello ? I already have established lactation and everything was fine: I was attaching my son, milk came in and the chest was empty after, normal))) For the last three days it's not clear what is happening. Milk is constantly there, I feel lumps. The son doesn't eat so much even at night, I have to express until relief. What is this and did you experience something like this?