DS is nearly 10 weeks old and ebf. It all started so well, then we developed some issues which people kept saying would work themselves out and now I feel like we're in a bit of a mess. 
I seem to have over supply in my right breast. It's frequently engorged and I've had mastitis from different blocked ducts twice in the past 3 weeks (I think specifically caused by DS sleeping for longer stretches at night and babywearing while engorged). The only time it ever feels like DS empties the rb is when the mastitis reduces my supply, before the antibiotics kick in. Normally within an hour or two it's stupidly full again.
Trying to relieve the pain from engorgement and unblock the ducts means I was hand expressing and nursing more from my right breast. They've been uneven since my milk came in but it's now worse and the left breast is about half the size of the right which makes me feel awful and self-conscious. I've been trying to feed more on the left to remedy this but I have to feed or hand express frequently from the right or it starts getting hard. I also have to feed DS every couple of hours at night for the same reasons, even though he'd sleep longer.
I have fast let-down in both boobs but DS generally seems to be coping better with this and is spluttering less. Reclining while feeding helps. I've always felt the letdown strongly but since having the mastitis I feel it quite painfully in both breasts sometimes. Other than this feeding is painless, and he is gaining plenty of weight.
How can I reduce my supply in one breast and even myself up a bit?!
I've read about block feeding but I'm not sure how to apply it when I'm so wonky. DS has always had short, frequent feeds, usually taking only milk from one breast before falling asleep or losing interest anyway. Is there anything I can take to reduce supply? I'm dreading getting mastitis again. Please help!