It may help to massage the lumps upwards toward your lymph nodes rather than down toward your nipple. This will help the milk break up but shouldn’t clog up your ducts x
Please express and massage it, you don’t want it to escalate I promise, speaking from experience
I had the same thing within days of my milk coming through! Having had mastitis with my 1st I wanted to avoid that at all costs. I used a haaka lightly suctioned and massaged my boob to relieve some of the pressure and release some of the milk. Massaged them whilst in the shower which again helped release some milk and soften them. I am now 2weeks PP and they've regulated to how much my baby wants. Just keep intop of it so it doesn't develop into anything worse.
If you have engorged breasts , you can use cold compress. You may have to hand express to empty milk ducts