MDS stands for myelodysplastic syndromes (plural) because it's a range of diseases. One of them is called CMML (Chronic Myelomonocytic Leukemia).
Here are more details:
There are multiple classification schemes for MDS. In the
FAB Classification scheme, which stands for French, American, and British, certain MDS patients are said to be in the CMML subtype. Some people refer to it as MDS/CMML to show both the disease and the subtype.
They usually consider an MDS patient to have the CMML subtype when he or she has 5% to 20% immature blood-forming cells (blasts) in their bone marrow and an increased number of the cells called monocytes in their circulating blood. Some MDS/CMML patients have low red cell, white cell, or platelet counts (I think you've told us that you have chronically low hemoglobin) although having low blood counts isn't necessary to be classified as MDS/CMML.