Putting May-Hegglin in this area of the boards is very appropriate as it certainly is a rare disorder!
One thing I always say is that often when patients have the impression that the doctor is "baffled", it's not usually the case. Platelets dropping with surgery is something that is seen quite commonly, and when it happens, rather than the doctor being baffled, s/he goes through systematic steps to figure out which one of the many possibilities could be the culprit.
The thing with May-Hegglin syndrome is that there are certain characteristic platelet abnormalities seen on the blood film and the diagnosis is usually confirmed by genetic testing. I wasn't sure about whether you were actually CONFIRMED to have the genetic mutation. Were you? If you were, well, then I guess you have the diagnosis right there, if you were NOT confirmed to have MH syndrome, there is another syndrome which is much more common in young women with low platelets and that is called Idiopathic Thrombycytopenic Purpura (ITP), which I am am very sure your doctors considered in the diagnosis.
ITP is an autoimmune disorder where the immune system decides to attack its own friends the platelets and can result in chronically low platelet counts. Usually the counts stay below 100 and above 30, but in times of acute stress (such as viral illness or surgery), the platelets can drop lower than that and put one at the risk of bleeding. ITP is somewhat a "diagnosis of exclusion" because you have to rule out other things before you call the diagnosis ITP. Things that are ruled out are: lupus and other connective tissue diseases, antiphospholipid antibody syndrome, HIV infection, heparin induced thrombocytopenia (if immediately after surgery) and disseminated intravascular coagulation (if after surgery or the person is VERY VERY sick). There are infections which can result in thrombocytopenia in isolation (i.e. low platelets) but they are usually viral. When other bacterial infections result in low platelets, they usually have effects on other aspects of the blood counts as well (i.e. on the red and white blood cells too) and there are usually signs of red cell destruction on the blood film (which would NOT be seen in ITP or MH).
If you have been confirmed to have the genetic mutation for MH then I guess the above was just interesting reading
If you haven't been, you should probably be referred to a general internist or a hematologist who will be able to monitor you. Usually with ITP, unless you have active signs of bleeding, have a platelet count <30 or are going to surgery, no treatment is required. Treatment regimens usually involve courses of things like prednisone, dexamethasone or IVIg.
Also, if you DO have the mutation, it would be considered a "de novo" mutation which is relatively more common in blood disorders than other diseases, and usually manifest in younger people (such as yourself).