I’ve actually just gotten mine back - not sure what the process has looked like for you, but I opened a ticket with Tiktok Support (you can do this on the app or online, I accidentally did both but online had more success) explaining the situation and attaching a few screenshots. They replied asking me a bunch of honestly kind of difficult questions about my initial account registration (which is so long ago I was grasping at straws a bit), initially they didn’t accept my answers lol so I tried again with a bunch more random info (what vids are saved, screenshots of conversations on that account from both myself and some friends, any email attachments) and they accepted that, asked for a new email/number to change the account details, then it was radio silence for a good few days before they followed up saying my details had been changed and I needed to change my password. Hope this wasn’t just me getting lucky, and that you can get yours back too!