I’ve been diagnosed with anemia?

hello I’ve recently been diagnosed with anemia , and due to a heavy period its been effecting me more. I have been taking the tablets given to me , however I have recently started to feel very ill and nausea even when sitting , my arms and legs feel very strange and ache . I have a slight odd feeling in my chest , I feel like a zombie all I want to do is lay in bed , I have no idea what to do , surely my tablets should be preventing this ?