Ahhh sabar lah mama, at 22+ weeks pening kepala with fluctuating HB is quite common especially second baby sebab badan dah tired, a few of us experienced the same thing. Doctor suruh makan iberet memang the right call, jadi follow je la; kena consistent minum and makan banyak yang kaya iron (daging merah, ayam, sayur hijau) together with the supplement. Minum plenty of water and jangan skip meals, and if pening gets worse atau you feel macam nak pengsan, call your doctor straight away okay, better safe than sorry. You're doing good, just take it easy and rest when you can, second pregnancy memang draining on the body.