Advice please

My son is 14 months old. He will be 15 months on May 4th. He had really bad reflux problems the first year of his life. He was behind on weight. He was behind on eating. It constantly threw up. He was always formula fed and on his 12 month well visit his doctor recommended to keep him on formula a little while longer, and my son will wean himself off the formula. I do half milk and half formula since 11 months old. He drinks 3-4 bottles a day now. Morning, nap time, after dinner, bed time. He’s much better with eating thankfully. But I feel like he will never wean himself off formula. I’m lost and don’t know what to do. He’s on the formula pictured below. I heard there’s toddler formula ? But I’m not even sure. I have his next well visit may 3rd. Any advice?