Girls who often carry a baby on their hands. Our little one is 3 month…

Girls who often carry a baby on their hands. Our little one is 3 months old. I ordered my husband to buy me a sling or ergonomic backpack. My arms are falling off and my back hurts. The child weighs 7 kg, and I weigh 46 kg. But still, my waist started hurting. Since she's not sitting yet, and doesn't come off her hands often. And so, according to a friend's advice, I want a carrier. Who has used it, what are your reviews?