I feel entitled to my mom's money
Why do you feel entitled to your mom's money?
While I waited for my mom to finish her degree my dad gave her some money that he saved.
You shouldn't be entitled to things you didn't earn. If your dad gave her the money from his own pocket then it is not yours.
You're right, I should have earned it.
Exactly!  If you want something, you need to show you deserve it.  I'm sure your dad might still support you in the future if you work hard to prove yourself!