My wife has had serious anaemia for some time (when I say 'serious' on seeing one blood results the hospital said if she were an inpatient they'd be giving her a transfusion). So I have some idea what it is like and how it can absolutely cripple you for doing, well, anything.
Taking things slow, frequent regular meals (no big pigouts), be careful when doing things such as walking up stairs (as you can be suddenly lightheaded).