drug test- scared im going to fail

so i smoke weed, a lot. my mom knew, and she never let me do it and i got in trouble for it a lot, but recently she found out how often i do it (every day.) I’m not asking for if it’s good or bad - the point of this is, after about a month of not smoking, i still failed a 50ng/mL drug test. she says i have two weeks to pass or else i get kicked out. for somebody who smokes like me, most sites say it can stay in your pee for ‘30 days or longer’- but i’ve found out it’s up to 90 days. i’ve looked at some detox kits but there’s a couple of reasons i don’t want to buy them- in 2 weeks, it’ll be a weekly thing, and no detox is permanent, so if i pass in 2 weeks, and then the week after that i fail, it’ll look really bad. another reason i don’t want to get it is it’s super expensive for something you can’t guarantee will work. a third is if my mom finds me with that, i’m dead. i’d like to pass naturally, but it’s not really up to me, more up to my fat cells and the way they process. i don’t feel like i’ll pass in 2 weeks, but i wanted to get some advice/opinions, maybe from other smokers who have had to take drug tests similar. thank you! UPDATE: she changed it to a month bc i convinced her it probably wouldn’t be gone in 2 weeks. a month is better but it can take up to 3 months, i know somebody whom it took 3 months for. but after a month that’s the final straw for her. she also believes i failed bc ive smoked after that day she caught me last, which i haven’t. thoughts? thanks :)