Hi Yinarii,
I would say that iron deficiency is at least part, if not all of the problem. Your iron stores are quite low and this is not unusual during pregnancy. In addition to the IV iron, you should also be trying to eat an iron rich diet, as much as your condition allows. To determine if thal minor may also be involved, you would need at least the results of a complete blood count (CBC). MCH alone cannot explain things, as it is low in both thal minor and iron deficiency. MCV, RDW, RBC count and other values are included in the CBC. If you have had a CBC, please ask for the results. Also, find out your Hb level. Are you also taking folic acid? This is an absolute must during all pregnancies. If you have not had a CBC, please request one now. These iron injections do normally work for iron deficiency but you should be aware that red blood cells take time to produce and iron deficiency cannot immediately correct the deficiency. Iron is needed to make new red blood cells, but the anemia will take some time to clear. Have you ever been known to be anemic before this pregnancy?
I would also ask any of the moms here if they've had to deal with hyperemesis gravidarum during pregnancy and if they have any advice on how to deal with it.