Your body is in a fasted state within 12 hours following your last meal. It’s easier to do water fasts after getting used to being in a ketogenic state. Ease into it, so first start reducing your carbs. Once you get to zero carbs then drop a meal, then 2, then all. Try 24 hours then 36, then 3 days. The first 3 days are the hardest! Water fasting really is more a mental game than a physical one because our lives are so food-centric. Water fasting can lower your blood pressure. If you plan on going more than 5 days, you will need to consider electrolytes and maybe a multivitamin. If you are feeling overly sick (some nausea and insomnia is common) then you should stop. Don’t think of fasting as starving because you are eating your fat stores for breakfast, lunch and dinner. #1 Rule of Fast Club is DONT TALK ABOUT FAST CLUB. People are well-meaning but not well informed about the benefits of fasting so just be coy about your weight loss.
High blood pressure is inflammation and inflammation begates inflammation. You need to find out why you have inflammation (ie high blood pressure and pain). I recommend you read An Inflammation Nation by Dr Sear.
The majority of inflammation is caused by allergies so I recommend that you see an allergist. I also urge you to check out the side effects of your blood pressure medication. The #1 side effect in most high blood pressure medicine is inflammation. (Is that not crazy?)
Lastly I urge you to go on a Keto diet (see Dr Ken Berry on YouTube if you need help starting.
An Inflammation Nation: The Definitive 10-Step Guide to Preventing and Treating All Diseases through Diet, Lifestyle, and the Use of Natural Anti-Inflammatories https://www.amazon.com/dp/B01H0Q2YMS/ref=cm_sw_r_cp_api_i_u-lpCbZK5189P