I work at a bank, you should have from day one removed all the funds and re-opened a new account under your name only. Then you could have easily just called customer service to close off the account. Removing someone as a signer does mean you need them there. But to close an account you generally do not need all signers to be present as long as you have transaction authority over the account.

Look I have social anxiety. I understand the feeling. But you are a 25 year old adult and you need to stop hiding behind your parents over financial decisions. It takes 45 minutes at most to open a new account. The most you will need is two forms of ID and the minimum deposit. Heck. Most banks now even have options to open accounts online and you just have to drive in for the deposit and drop off any additional documents they might need.