It's not your fault. They either don't understand or are too selfish to care, that you're not choosing to be this way. Frankly if I heard something like that from a therapist, I'd report them to licensing authorities because it'd be wrong and highly inappropriate of them.
I'm not in a position to give advice on what to do next, but I had to let you know that you shouldn't blame yourself for things beyond your control. What you need isn't to magically "get better" as if someone born without legs can just "get better" and grow new ones. We put access ramps around buildings, why not the psychological equivalent?
Find some people who understand and are willing to help. Don't believe the victim-blaming. You're not alone!