We're not alone!

Personally, I have come across very few people, including medical professionals and lactation experts, who know a lot about overproduction, or what to do with it.  Non-professionals haven't heare too much about it, either, and it can be a lonely road when you feel as if no one understands what you're experiencing, much less offers help!  So when I read this article,  in the International Breastfeeding Journal, by Caroline GA van Veldhuizen-Staas, I felt a sense of relief -- this woman gets it!  Even rereading it today, I feel a certain relief at the thought that she understands the things that I struggle with as I breastfeed.

Methods to treat real or perceived low milk supply are well referenced in the literature      Overabundant milk supply or hyperlactation on the other hand is not discussed in depth in the literature. There is no consensus on treatment or terminology. However, overabundant milk supply can be as devastating for the continuance of breastfeeding as underproduction.

So I'm not the only one who couldn't find much help for overabundant supply.

The hyperlactating woman will often experience a constant feeling of (over-) fullness, engorgement and tension. She may leak milk in between feedings, or leak copiously from the opposite breast during feedings, and has an increased risk for mastitis. 

When I say that she gets it, I mean it.  And she understands the baby's problems with the problem, too:

The infant may appear to be a greedy feeder, struggling not to choke or aspirate milk. He or she may often spit up after feedings and/or have reflux-like symptoms, and suffer from intestinal gas, colic and explosive, often green and foamy stools. The baby may show either a very low or a very high weight gain. The baby's struggle to cope with rapid flow may result in restless nursing behaviour, or even aversive behaviour, such as breast refusal or shortened feeds. Fussiness, crying and possible low weight gain can lead the mother to think that her milk is insufficient in quantity and/or quality.  

...A common secondary symptom in hyperlactation syndrome is a sub-optimal nursing technique in the infant. This may be the result of the child's attempts to cope with an overabundant milk flow, sometimes slipping from an optimum latch in order to clamp down on the nipple to slow the flow, often traumatizing the mother's nipple in the process. Or the infant may develop a conditioned habit of drinking but passively suckling at a breast that will give milk without any effort by the infant itself. This has the potential to lead to supply problems after 4–6 weeks when supply stimulation patterns transition from primarily hormonal stimulation to feedback inhibition mechanisms.  

After many, many months of having to piece together small bits of information here and there about overabundance and its resulting problems, I rejoiced to find an entire article -- scholarly, at that -- that discusses in detail these difficulties.

She talks about some of the physiological mechanisms that regulate milk production, as well as some of the common treatments, including block feeding, which I've found to be extremely effective in my own attempts to regulate supply. 

She then offers a new technique that she's developed, and describes some case studies that have used the technique.

 The treatment sequence starts with an as-complete-as-possible mechanical drainage of both breasts. ...The infant will latch on immediately after drainage and will be offered both "empty" breasts to satisfaction. ...Subsequently the rest of the day is divided into equal time blocks starting with about three hours, initially. Every time the infant shows hunger cues or other signs of interest in the breast the same breast will be offered without any restriction in either frequency or duration of feeds. At the end of such a time block, or after a multi-hour period of sleep, baby will be offered the other breast for all feeds within the next time block. ...Depending on the seriousness of the symptoms time blocks may gradually be increased to 4, 6, 8 or even 12 hours. For less complex situations one-time mechanical drainage will suffice; for others occasional repetition may be necessary. Intervals between drainage will gradually increase as the symptoms lessen.

When I found the article, I was already well into my breastfeeding relationship with my youngest, so I haven't tried this technique.  However, if I have more children, I will definitely try this method.  I would probably even try it now (my nursling is almost 20 months), except that with other babies, I experienced a huge decrease in the effectiveness of pumping after 12 months -- my breasts just don't react to the pump as they do to the baby after that time.

I highly encourage you to follow the above link and read the entire article -- it's fascinating and not too technical, and can make overproducing moms feel a bit more understood. 

She concludes her article with this statement:

 More research will need to be done to understand why some women will easily produce much more milk than needed and why for some it is so hard to regulate milk production to meet the needs of their children.

I totally agree.

International Breastfeeding Journal 2007, 2:11