I'm 10 months postpartum.
It wasn't until my son started sleeping more at night (2 quick night feeds) that the weight started to shift. Lack of sleep takes a huge toll on weight loss - being an insomniac is one thing, but when your body NEEDS and WANTS sleep, but you cannot because of your babies, it's much worse.
I would suggest higher calories - I am losing steadily on 1400. Your body needs energy and fuel when you are still so soon postpartum (I assume you are not nursing if your calories are so low), plus you are working so much and exercising, you will burn yourself out.
It takes a long time to shift baby weight. Be consistent, focus on getting the rest and eating well but not too little, and more time!!! Good luck!
And lastly, you will be lucky to see .5-1lb per week loss at the very most at your size. No more than that or else you're dealing in muscle loss and subsequently, a smaller but still jiggly figure. You want fat loss, not muscle loss. Daily fluctuations are 100% normal and not a sign of fat gain.
Also you say 'babies
' - twins? That must be so much more difficult. Please give yourself a reasonable time frame
I'm reaching my 'satisfactory' figure at 10 months, nowhere near it at 5 months! And I work darn hard!