Diastasis Retci

You need deep core restoration, things like crunches wont help. Look at 360 mama on instagram

I would start with pelvic floor physical therapy.

How large is your gap? If it is 1-2 fingers you can definitely close it with modified core workouts. I closed mine but I took several months and I still have a bit of coning with sit ups at 1 year pp. No planks, no crunches. Lots of cat cows, dead bugs etc. Start with core workouts on your back where your core is more supported (gravity isn’t pulling in down)

PT and time don’t worry you going to recovery