My Earned income credit was $6,269 and my child tax credit was $1,870. Totaling $8,139. How come i only got a return of $5,788?

Was the 5,788 the refund on your tax return line 76a?  Or what the IRS sent you?
You get the credits but you still have to pay any self employment tax on line 57.

You did claim all of your self-employment income and expenses, right?

Yes I did. I claimed it all

https://ttlc.intuit.com/questions/3821776-preview-my-1040