Frequent clogged milk duct help!!!

Katarina

My little girl is 8 months and a great nurser however for the past two months I continually keep getting clogged milk ducts in my right breast. She doesn't nurse that side less and I'm stay at home so she nurses every three hours. these are becoming so painful and I'm always scared it will turn into mastitis but even aside from that it is excruciating. she doesn't like to nurse when I have one because she has to work too hard to get milk from it so I keep having to try and massage it out and it barely works by a full day of dealing with it. but this is the fourth time in two months !!! help please on any other tips to avoid this.