Chris, ... ... Great job for fasting with water only, for 3 days and choosing this path, and that...
Great job for fasting with water only, for 3 days and choosing this path, and that at age 16. Also great that you realize that you need lifestyle change.
It takes a long time get the we are and it will take a long time to be fixed. Perhaps years.
First, for this fast, rest, stay warm and drink warm distilled or filtered water. No supplements, no toothpaste, chewing gum, etc. just water. Use tongue scraper to keep your tongue clean. Take one day at a time. Don't despair if you fail. You will face detox symptoms, headache, backache, nausea, sleeplessness, etc. but not all at the same time. So when you have one of these symptoms, the key is to know it will pass, will it out.
Second, once you finish your fast, make sure you break it with freshly squeezed organic orange juice, or watermelon, tomato and build up the appetite slowly. Stay on plant based diet. We in the western world eat too much high protein and animal products. Plant based foods in raw form are cleansing.
After you have eaten lime this for a month fast again. While you are eating cleanse your kidney, colon and do a liver flush. You need to get toxins out of your body.
I don't know your height, but you should weigh 150lbs. You will get to that goal if you keep your focus on it and be in this journey for a long time.
Fast, eat plant based foods, fast again.