I'm currently 125 lbs and I'm 5'ft tall and I want to lose 20 kg and be 88 lbs. So what are some ways to get this results in 4 months? My dream is that when I sit down those layers of fat in my stomach won't be there?

I'm sorry but that is an incredibly unrealistic goal. If your stomach was flat when you sit down, how would you stand up? Your skin would be all stretched out. It wouldn't work.

This 'goal' is severely unhealthy, as you are already VERY underweight. The NHS has guidelines on height and weight on their website. http://www.nhs.uk/Livewell/healthy-living/Pages/height-weight-chart.aspx