It’s not healthy (it ruins your teeth, heart and can ultimately kill you), and it also limits your weight loss. Your body goes into “emergency” mode and ends up trying to store all the fat it can.
The most important thing is to be healthy. Exercise regularly; go for a run, a swim, a bike ride. It not only increases your metabolism and hence helps you lose weight, but it also means that your losing the weight that you want to lose (if you lose weight by throwing up, your body will burn off muscle, not fat). In addition, exercise makes you feel great afterwards!
Eating is another factor. Make sure to eat regularly; if you starve yourself, you’re more likely to over-indulge and make yourself vomit after. Also, to lose weight healthily, eat vegetables if you feel hungry. They full you up, but have few calories and are incredibly nutritious.
The key is staying HEALTHY. If you can’t stop yourself from throwing up, go to your doctor. They should be able to help you - and keep you safe, which is the most important thing.