I don't see it as you are living a lie tbh. I see an individual that had an illness that challenged their brain, it took time for that brain to rewire to accomodate in spite of that challenge. You have been growing and gaining this entire time. As far as not feeling or distancing from being emotional when your mother got ill and died, you just did not know "how" to deal with that experience. What you are feeling now is simply a delayed grieving because you have had time to mature since then and you are "ready" to finally mourn that loss.

People often feel as though they are somehow faking or should be more self aware than they have been, all that means is that person is ready to become more self aware, it doesn't mean they are a "pretend" person really. Your mother would have been so proud that you achieved so much, that is what every mother wants for her child, why she protected you too so you would feel safe while you worked on growing and gaining. The human brain is pretty amazing you know, can compensate and rewire itself in spite of injuries and strokes even where areas can suffer damage.

I think seeing a therapist to help you with this is a good idea.
You have just come to a point where you are finally ready to talk about it, heal and grow.