Thanks for reaching out, TaraC70. We can definitely help you with cancelling your subscriptions.
In the same way that removing a physical mailbox would not cancel a magazine subscription, uninstalling the iTunes app on your computer will not have any impact on monthly subscription charges on your Apple ID account. Instead, you'll want to use iTunes to cancel the subscriptions you are signed up for. Go ahead and follow these steps when you Use a Windows PC to cancel subscriptions from Apple.
If you don't have iTunes any longer, be sure to download iTunes for Windows first.
Hope that helps!
Take care!