I just want to cancel my $.99 50GB per month cuz I don’t need anymore I have unlimited

Start here: Downgrade your iCloud storage - Apple Support

See this article: https://support.apple.com/en-us/HT207594

I don't know what you mean by 'unlimited'. There is no unlimited subscription to iCloud. The 50GB costs you $9.99 per month to maintain: it doesn't increase each month. The method linked to above by my esteemed colleagues will revert you to the free 5GB level, and if you have any data there in excess od 5GB it will be deleted.

If you are talking about unlimited data from your carrier that is completely different than paying for the extra iCloud storage. If you are paying $0.99 for 50GB of iCloud storage and cancel it then you will only have 5GB of iCloud storage available.

50 GB is $0.99 per month.

Indeed it is. The decimal point must have crawled across while I wasn't looking.