It may be a good thing: muscles are heavier than fat.

Please don't starve yourself, you need fuel. Eat vegetables and low carb fruit, chicken, turkey, salmon, tofu. The main thing is to avoid or limit high sugar, carbs, and alcohol. Stay hydrated by drinking water frequently. Also, don't exercise to intensely and for too long to avoid unjury. I advise to consult with your doctor on how to lose weight properly for yourself.

Losing weight hack: Be on a caloric deficit. You can enjoy all the foods you want, just in a smarter way. Use “Lose It” to count calories and keep track. Do this with excercise 3x a week and you’ll see long term results. If you starve yourself it will cause you to binge eat and your results go out the window. Prioritize protein above all else to build muscle. Don’t worry about the number on the scale, this fluctuates on a daily basis. Once you stick to a routine you will noticeably see results.

Your body was holding onto fat because you weren't eating enough to keep you body properly fueled.

I had the same issue for a long time. I would eat 1200 calories and gain and gain.. I finally figured it out and am losing weight. I eat twice as much now than I did before. A lot of protein and veggies. Carbs in the form of legumes or fruit instead of pastas and breads (in moderation). No snacking. 3 full meals a day. Dropped weight without even feeling hungry.

Starving yourself slows your metabolism, which makes you gain weight.