Belly button mess up post tummy tuck. Is there anything I can do to fix this? (Photo)

I would recommend waiting at least 6-12 months before doing any revision of the umbilical scar. Things will continue to settle down and the swelling will resolve. It will at least 6 months before you will know what the final shape of your belly button will be. The hardest part is just being patient will the healing process continues. Time is usually your friend in these scenarios. Stay in touch with your PS throughout this process so he/she can give you advice. Best wishes. 

Five weeks is way too early to evaluate this. Wait at least 4-6 months before judging. Some of the result we can achieve is limited by the existing structure of the actual umbilical stalk. Basically, we can only shorten the stalk if warranted and obviously shape the skin opening for that stalk to "peek out" from. If changing either of those things would ultimately make you more satisfied it could be done under local anesthesia at the proper time.