Its about planning. In your situation I would say $2.5K is approaching too much of a "set aside" or what some people would call an emergency fund. This money should only be used in emergencies.
In your case you used this fund for all kinds of things that were not emergencies. Car insurance, car payment, rent, security deposits, groceries, and furniture should have all been planned and therefore budgeted. The same sort of thing with car maintenance, utilities, clothing, and holiday gift giving. Plan for these items and you won't see your hard fought savings depleted.
The magical formula: Adding the anticipated expenses! You should probably look up some resources and guides to budgeting. Getting good at budgeting early will help you succeed in life.
You may want to call your parents and thank them for taking care of all these things for you while you were growing up.
Given that you recently graduated college I must assume you are somewhat success minded. If so why in the world would you have a car payment? Although the idiot box will tell you that you cannot be a person of significance without a brand new car, wealthy people will tell you different. I recommend reading two books: "The Millionaire Next Door" and "Stop Acting Rich" if you are remotely interested in becoming wealthy.