Weight loss

When I was pregnant my last weight taken was 220lbs. Then I had a 10lb 3oz baby boy and i went down to 200 in 1 day. By August 20th I weighed 180lbs. And now I’m down to 176lbs but I can’t lose anymore weight. I still need to lose about 46lbs to get to my healthy weight for my height and it’s pretty much impossible and frustrating. What should I do??