Does the "I" get unified with the Totality in the end?
No. There is no “I” that is separate.
That separation is an unexamined assumption that about seven billion people go for without a second thought.
So any spiritual idea concocted around that assumption is either pointless imagination or geared toward a certain type of seeker early on the path.
For the mature seeker it is stated that what we call “I” is a concept associated with a personality, ego and a body and has a practical function in life. But it was never separate from Consciousness.
Awakening is the event when that assumption is uncovered and possibly destroyed.