Why am I getting milk ducts clogged again and again?

I'm sick of this!! I used to have this problem on the left side. Now that is fine and my right doesn't go one night without getting painfully clogged! My son is 18 weeks, I feed him every 3 hours since I wouldn't dare to skip, I have a full freezer of milk and still I'm producing so much I'm sick of it and it's getting very painful! Is there any way how to decrease the milk production??? Less feedings won't work with me and I'm afraid I will never stop feeding which I hate now really bad!!! Any ideas???