Ooh, OP, I felt like you at 37 when marriage broke down and I had two children.
I can tell you what I did, which really helped tp find 'me' again.
I started a list and as I thought of things, I added them to it. I included things I wanted to be and wrote them in the present tense as though they described me - even though some didn't. Everything was phrased positively so, eg, rather than "I want to lose weight" I wrote "I am a healthy weight" "I exercise" even though neither were true at the time!
Then I colour coded everything - green was stuff I could change immediately like "I have well kept nails" and "I eat healthily". Orange was stuff that was mid term like "I have a job I enjoy" (and I started looking immediately). Red were longer term plans "I am in a loving relationship".
I tried out new hobbies - BMF, yoga, choir, swing dance classes, joined a band etc. Some stuck and others didn't.
I remembered all the things I was and did before I had children and decided which of those still resonated with me (eg music).
I wrote down everything - the food I liked, the films I liked, my political leanings, my friends. Everything.
I asked people I trusted to give me three reasons they liked me (that was an interesting revelation!) I asked a mix of men/women; people I'd known for longer, people I'd only recently met. Didn't make it a big deal just told them it was an exercise I was doing for therapy and left it as that. I only asked people I thought would participate in the spirit of it, and that's why I asked people I trusted.
It gave me a really holistic view of myself. I remembered things about myself I'd long lost or forgotten. Nobody thought it was strange.
That was 12 years ago. I'm in a job I love in the career I trained for when I often wondered if I'd made a mistake before. I have a partner I love and who loves me. My children are thriving.
That's what I did and it worked for me.