Ever changing life

I realized today that I don't know who I am. I've spent so many years identifying with my job and my role as a mother that now I don't know what I'm about. The job is still there and I will continue to advance and grow in that but with one child having graduated and moved on and the other having gone crazy and moved on I don't know what to do with myself. I find myself focusing all my non job related energy on my relationship. Noticing and obsessing on every nuance. Every missed phone call, every happy moment, every un said thought. It's not healthy and it's because I haven't filled the gap.
Knowing now that the gap must be filled I have no idea what I want to fill it with. I don't know who I am any more.
My mother warned me about this.
It's like a pre midlife crisis. It sucks.
It is a new year one filled with possibilities. I am my own woman again I just have to figure out what that looks like and I'll be fine.
I hope