Yep - don't take anything, but eat healthier if you want to be healthier.
Supplements, shakes, powders, etc are designed for athletes that are pushing themselves at their limits.
You are not at your limits. You need to start a regular exercise routine, let yourself grow properly and make the changes gradually.
If you're impatient then it's time to suck it up and stop being so. Making yourself healthy needs regular attention for a long time, and that's a cold, hard fact. Cut out the bad food, eat good food and start building exercise (like swimming, not pumping iron) into your life.
See how you feel after that, and if you're still not happy when your body has found it's natural healthy shape then I suppose your doctor will advise you on the best way to go about things. Good luck!