I'm sorry you are struggling with anemia. I have not had any issues with anemia, in fact I had my hemoglobin checked a few months ago to screen for something else and it was very healthy after years of being vegan.
However, I was diagnosed with osteoporosis (via DEXA scan) in 2006 as an omni. It has gotten worse over the years, even as a vegan, despite conservative treatments. I am now on a fairly toxic, powerful shot to stop progression. I had held off on it for 8 years and my spine T score went from -3.0 to -3.6 and I was suffering chronic bone pain and suspect fractures in my pelvis. So I had to do something more drastic. I do understand that it can be a challenge to manage some conditions where diet makes a difference either positively or negatively. I have to be very diligent about meeting my calcium/D/magnesium/and other bone building mineral needs. I try to get as much from diet as possible because my body can't handle many supplements. And with the shot I am on, I HAVE to make sure I have enough blood calcium because the shot pulls calcium from the blood and puts it into my bones. It is not an option and I have my vitamin D and blood calcium checked before every shot. Vegan sources of calcium are abundant but not as high in calcium as dairy per serving, so it means eating more of them each day.
It sounds like your anemia actually started as an omni? Did your doctor give you any indication of underlying reasons? Do you have heavy periods (assuming you are female)? Or other intestinal absorption issues? How is the ferrous sulphate working for you?
I eat a lot of leafy greens daily for a variety of reasons...calcium, iron, etc. Beans are a good source of iron, and soy foods. Wheat germ is also, and some nuts/seeds. Blackstrap molasses is an excellent source of iron and even calcium. I use it often. Getting a high amount of a vitamin C source when you consume iron rich foods will also help with iron absorption. For example, a salad with kale or spinach in it could also have orange slices or red bell pepper slices in it as a vitamin C source that would aid in absorption of the iron from the kale. A hot cereal sprinkled with a few tablespoons of wheat germ could also have chopped strawberries or another berry mixed in there too. I like to make orange tofu stir fries and use blackstrap molasses in my sauce, along with fresh orange/juice. Plant sources of iron (non heme) are abundant but can be harder to absorb than meat sources of iron (heme). So adding the vitamin C is important. Limiting coffee and dairy products when consuming plant iron foods (or your prescription) is also important to help with absorption. It is easy for me to share all this having not suffered with anemia myself. I think it would be important to make sure you know the reason for the iron deficiency anemia. Is it really because of being vegetarian? If so, then it would be a simple matter of increasing iron rich foods and being diligent about it, along with steps to make sure it is absorbed. If there is another underlying condition it would mean treating that. Of course, I understand that the human body is complicated and it is often not just one problem. This is the way it is with my osteoporosis. I have long term hypothyroidism (diagnosed in 1989) and have been on thyroid meds for many years and that contributed to my bone loss. I was underweight, sometimes severely so, for over six years which also contributed. I lost my ovaries eleven years ago in 2005 and went into abrupt surgical menopause which accelerated my bone loss. It took me three years after that just to find a hormone replacement my body would absorb and that made me feel human again. I can do something about the hormones and weight, and have, but the thyroid stuff is a bit more tricky. It also means I have to be careful with soy consumption, which happens to be an excellent source of iron, calcium, protein, so I have to find a happy balance and keep my vegan diet varied.
I hope you start feeling better and get back to being your healthy self! There is no shame in having anemia. It is not an uncommon condition. HUGS