I would take Bella to an opthamalogist at some point for a second opinion. They have much more sophisticated equipment to evaluate her eye.
Even if you do get pet insurance, it would probably be considered a pre-existing condition and not be covered. It's a very long surgery and I'm sure very expensive.
Are you home during the day? Putting artificial tears in her eye every 4-6 hours can help prevent ulcers and give her some relief.