Extremely frustrated with personal statement and AI checkers!!

So i made a post a while ago and used chatgpt and grammerly to help me write my essay and brainstorm and revise. I got 87% chatgpt. So i was like okay i need to rewrite the WHOLE thing from scratch, i even checked alot of stuff and i typed it in front of my brother’s eyes.

After working 6 hours on it, i see it was 20% , i keep working on it to make it more concise and reduce word count etc.. and i work on it another 6-7 hours make sure my concluding paragraph is good. After about 13 hours of authentic work it goes to 70% again. I don’t understand 😭 also pls keep in mind that this happens whenever i add simple commas or punctuation or when i try to make it conscise , doing advanced search on gptzero, it keeps changing from human to ai very fast by adding one word (HUMAN WORDS - MY WORDS)

Please help! I am beyond tired and burnt out and i’m really sad that my work is getting flagged.. my friends who actuallyused all ai are getting less % of ai. 😢