Maintenance dose and extra needles... advice needed!!

Hi all! I'm currently 4 months into my mounjaro journey, and unfortunately, due to financial difficulties, I can only afford one more month. I've heard stories about people coming off without a maintenance dose and regaining, which I'm terrified of- I've lost over 15kg and would hate to regain, but I just can't afford a maintenance dose. I'm currently on 12.5mg, which I've found is too much for me. My thinking is that, if I buy additional needles, I can give myself 2.5mg a week, which will stretch out the mounjaro I have left and provide me with a maintenance dose to wean myself off. Does anybody have any experience with this? And if so, how should I go about sourcing the correct needles? Any help much appreciated :)