Did you remove it only on your computer/twitch client but not through your account where the modpack is still accessible on the curse site? Try removing it from the modpack page if possible/removing the modpack page itself if you can remove it that is. I myself am not sure but I assume it's possible to close one down.
Just checked myself and there is a 'delete project' option under the settings tab for that project.
Niche Mod Finder/Acknowledger/Tester/Player. Fan of Datapacks, Rift 1.13/1.13.2 Mods, Fabric 1.14 Mods and interesting underrated or new 1.12.2 and below versions of mods. :) Testing 1.13.2 Forge and Fabric 1.14 mods mostly though.
I sometimes create the odd modpack or adventure map once an idea comes together.