Blocked milk duct - how to not get mastitis?

CC

I need to try avoid getting mastitis.. 😳 I exclusively pump and I’m 99% sure I have a blocked milk duct I can’t get rid of.

I’ve sat in the shower under hot water and hand expressed rubbing out the lump, I’ve tried pumping and rubbing it at the same time. I’m not sure what else to try?

The lump is hard and the area is red but it isn’t painful unless I touch/press it.

How concerned should I be? Should I go to the dr or try other things first?