@SheriGR I don't have this many issues removing buffs. But you can't remove all buffs from a Sim because buffs are also in relation to the plot, surroundings and so on.
I hope i won't be to late to help you out
@RileyBess755.
When you removed the clear and probably coloured buff 'possessed', you probably did not remove the accompanying other buffs that go with the trait or trade. So, try to find the dazed and/or other buffs and delete them one by one until your Sim looks normal again. Use MC cc as you did in the first place.
I sure hope this will work for you. If not you should definitely consider
@SheriGR 's options.