How do I get my money from my deceased mother's bank account? I really need it!

I was mothers caregiver for 5 years, I opened an account for her SSI with only her name and deposited my own money to help cover rent, she died on 1/29/09 and without thinking I deposited money on 2/2/09 to cover as usual, SSI was cancelled and bank account closed, because I was not on the account , how do I get my money, I really need it!