Advice please!

Does anyone have any experience with diastasis recti (separation of abdomen muscles) and umbilical hernias? I have had the separation of abs since my second pregnancy without symptoms. Several weeks ago, while doing 30 day shred I began having pain above my belly button, thought it was from muscle gain, then small lump appeared. I can push it back in but I'm reading conflicting information about exercising core to strengthen and repair hole in muscle, and I've read that this needs to be repaired surgically. I know that many of you are not physicians, I know that if it becomes painful, hard or increases in size to see a doctor right away. I do not feel pain while exercising since the first several days after initial pain. I just would really love to abound surgery! Has anyone had this happen? Can I strengthen my core enough to repair this myself?