Early Developmental Traumatic Brain Injury

Has anyone else had a childhood TBI early in development that went undiagnosed until adulthood?
I have been through the ring with doctors diagnosing and rediagnosing and have finally been told by a specialist that I have TBI. I fell from a table onto a cobblestone floor when I was 3months old. I have been told that it altered my personality completley, but at such an early age that no one had any way of knwoing. And that the studies and treatments on this are new.
I was told that when I complete the treatments I will feel true emotions like grief, fear, sadness, being tired, and whatever else for the first time. That I will feel what it is like to be hungry and full. That I will have a sense of time and speed. That I will feel physical pain ect.
He said that when patients like me complete treatments they typically have to be coached through the emotions they experience and that the emotional span can be tweaked because sometimes it is overwhelming. He said that internally I will be drastically different, but tried to reassure me that my mannerisms and the way I act outwardly will not change because of a lifetime of habit.
Has anyone been through this and can anyone tell me what to expect?
All I can find are either parents talking about their children they are treating, or adults who had a TBI in adulthood.
No one who can explain what the process was like after a lifetime of functioning completley different than everyone else and essentially having no basic instinct or emotion without knowing so.