HELP HAND RAISED BABY HEDGEHOG

Hello all!! I had an unexpected situation where a mother abandoned her children at 4 days old. I had to try to hand raise them. One of them passed from an RI and the other got an RI I was successful in treating the last surviving ones RI. His name is Elliot and he is my little pride and joy. I was so so looking forward to the three week mark to start weaning him so I could get my sleep schedule back…well there’s an issue…Mr. Elliot is tiny in size currently only weighing in at 62g at almost 5 weeks old. He will be 5 weeks old tomorrow and although he continues to gain weight he REFUSES to take anything other than his formula and sometimes mixed with rice cereal. I JUST NOW got him to sometimes lap it up out of a lid but most times he will lap it then refuse food until he gets a bottle. I’ve tried everything from pate cat food to chicken baby food….he spits everything out and at best anoints with it. I’m at a loss as to what to do….I’ve tried putting it in his mouth and all he doesn’t want anything to do with anything that’s not his formula. His stools are soft and I believe it to be because his formula is still his only diet so I tried giving a bit of pumpkin and a bit of banana to try to help but he refused pumpkin and only licked the banana to anoint with it 🤦🏻‍♀️ PLEASE help this hedgie momma as I have no idea what to do! Below is a photo of my stubborn little booger butt!