Help me lose muscle/fat {fast} (tips?anything)

you dont need to loose weight you need to get HELP 1st off you sound UNDERWEIGHT which can be dangerously unhealthy for you life, health, development, fertility, ect and if you learned abything about the human body you should know that

1. weight loss does NOT happen fast there is NO quick fix healthy eating and regular exerscise is the only right way to loose weight everything else will either leave you weak and unhealthy or youll end up putting all the weight back on, and then some weight loss happens GRADUALLY it takes MONTHS to loose weight not days and you certainly wont see ANY results in 3 days also you cannot just loose muscle to do that you need to not exerscise so that your muscles litereally waste away which will make them smaller, weaker, and make you put on weight and as I said before you sound underweight meaning the last thing you need to do is loose any more I strongly recommend you first see a doctor and get your bmi (body mass index) calculated for your height and age he/she will be able to tell you what weight range your in and how much you need to loose/gain to be in the healthy weight range