Hello, thanks for reaching out.
The main problem is you cannot access the old Hotmail email you used to set up the account. Have you checked if you still have a recovery option like a linked phone number or alternate email for that account?
If you cannot recover the Hotmail account using the recovery tools, the account cannot be restored. This means you cannot confirm your Discord email through that address.
Your best option is to contact Discord support, explain the situation, and provide proof of account ownership so they can help you change the email or recover access. You can try Microsoft recovery here: https://account.live.com/acsr and reach Discord support here: https://support.discord.com/hc/en-us/requests/new