The Mahasi approach of practicing dry insight for ~16 hours a day is unnecessarily grueling and stressful. You would be better off developing jhana before attempting insight practices, per the Buddha's instructions in the Pali Nikayas. Jhana brightens and clarifies the mind, which "primes" the mind for insight and makes it possible to attain stream entry with minimal effort. You will also experience bliss and relaxation whenever you want.
Pa Auk Forest Monastery in Burma (
http://www.paaukforestmonastery.org/) is the most popular in Asia for jhana-focused practice and instruction. If you'd like to know more about developing concentration as a preparation for insight, The Mind Illuminated by John Yates (
https://www.amazon.com/dp/B01INMZKAQ/ref=dp-kindle-redirect?_encoding=UTF8&btkr=1) and Right Concentration by Leigh Brasington (
https://www.amazon.com/Right-Concentration-Practical-Guide-Jhanas-ebook/dp/B017JJOXQ6/ref=pd_sim_351_2?_encoding=UTF8&psc=1&refRID=RY27FV9GK0DH6825880R) are solid guides. Let me know if you have any questions, and best of luck to you.