40 Day Water Fast

Hi guys I started a Water Fast 9 days ago. I will be on my 10th day tomorrow and purpose is complete fat loss. I am aware of the detox and other benefits but they are just added bonuses to me. So far I have lost 7 kgs and having said that I transitioned to Water Fasting from intermittent fasting(IF) with a keto diet. I presume that most of my water weight was gone before I entered water fasting. My beginning weight before IF was 131kgs and today morning it was 119.2kgs and I intend to get to 90 kgs at least by the end of 40 days. I am sure most people would feel that this is unrealistic but I wanna smash through all the pain and hunger like a mad bull. Mostly I workout everyday which consists of 30 mins of treadmill( 3min walk and 2 min incline) and 3 exercises of a body part with 4 sets and 10 reps just to stimulate the muscle. I haven't had any headaches just slightly light headed when I get up and no difficulty at all working out and consume 10 to 12 L of water each day. My only problem is extreme hunger and major dip in motivation at night. Also I get heartburn and acid work at some point during the day which I drown using water. I would love it if someone could support me through this and give me any tips at all to sustain my goal, for which I would be eternally grateful. Cheers!!