How do I fix my distended abdomen? Is it my core strength or something more? (photos)

Thanks for your question.  After having babies, some women develop a gap between their abdominal muscles called a rectus diastasis.  A plastic surgeon would be able to tell you if this has occurred.  Generally, strengthening the muscles will not make a diastasis resolve, but there are surgical options.

If there is an issue with abdominal wall laxity, surgery would be appropriate.  I
would search for the board certified plastic surgeon who you feel is
most likely to give you the best results and who performs hundreds of
these procedures each year. I would look at patient reviews as well as
before and after photos on that surgeon's website.Kenneth Hughes, MDLos Angeles, CA