Hi a few years ago I took shahada. When u said it I was only sincere about the part 'there is no god but allah' but when I spoke the part about the messenger I wasn't fully sincere as I didn't feel totally convinced. My mum came with me but she wasn't happy with what I was doing so the whole thing felt uncomfortable and at the time I didn't know much about Islam I'd never even opened a Quran and in the end I stopped praying and went back to my old ways I kept saying I'm a Muslim but didn't fully feel like one. I'm now questioning whether I actually converted since only part of it was said sincerely. I'm now taking my time to learn about Islam but the question of whether I really converted keeps nagging at me
لا إله إلا الله محمد رسول الله
Regardless of whether or not your prior shahada was accepted, if you want to be a Muslim, then say the shahada.
Whether or not Allah accepted your initial shahada (and you "need" to say it again) is between you and Allah.
(Oh... and welcome to Islam.)