You're "rationalizing" stopping because of the weight/metabolism thing and that is just not a valid rationalization because whether fasting or not the fact is that if you want to loose weight you'll still hafta exercise and eat right regardless. Just that when you fast the exercising is crucial to bring the metabolism back up.The other thing is that you are NOT "starving". Your system is in fasting mode and producing ketones. Totally different thing. Do some research and find out how "fasting" actually works. What fasting will help you with in regards to loosing weight is that you are eliminating toxins and other debri from your system thus your system will operate more efficiently post fast and you will be getting more nutrition from less food. Tain't rocket science. It's a matter of educating yourself and understanding how it all works and how to use fasting properly and what you hafta do post fastif weight loss is your goal.
On the broth well you do the best you can and maybe use some good quality canned veggie soup and strain the solids out. Not the best thing to do but if it's all you got you do the best you can with what you got. Can you get anything like fruit smoothies? That could be a possible alternative.