Fiancé Newly Diagnosed. Not sure I can deal.

This post is part rant, part seeking help and ideas.

I grew up with a brother and a mother who were both diagnosed with ADHD right around the same time (1991 when it was "all the rage") so I've essentially been a mom all my life. About 2 months ago, my fiancé was diagnosed with ADHD. We've been together for 4 years, and we've lived together for a year and a half. I've always been easy going and the opposite of a nag. With him, I feel like the uptight, nagging mom all over again. We are going to therapy together and he started a low dose of Aderall. Today (after forgetting to fill his Rx on Monday) he was to up his dose with his new Rx but the pharmacy won't have it until Tuesday. He is completely without meds and he has a deadline for work this weekend. His ADHD is ruining his career. In the last year it seems he cannot maintain a job more than a month or so at a time. He says he cannot work without his pills and he said he's afraid he's come to rely on them. I've done so much research to find other ways to help him, but he refuses to try anything but the pills and basic talk therapy. I feel like I can talk until my face turns blue, I don't feel any better and I am trying to accept that this won't change. I can deal with my mother's ADHD, she works hard to keep it under control, and she's worked hard to give me everything she could as a mom. My partner just wants to throw money at everything to make it 'all better' but he's not making any money because he can't keep a job. He can't wake up on his own. He can't take his pill without me handing it to him. I cannot ask him to take on any responsibility without a tantrum followed by forgetting to do it (he agrees that the accurate word for it is 'tantrum'). He can't - refuses to - cook, he can hardly do his own laundry. He is incapable of functioning as an adult. It feels as though he turned 15, having been catered to and pampered his whole life, and stopped evolving. I'm told I am incredibly patient, but that's not enough. I just don't know what I can do to ease this situation. I am about to start a new career that involves being a full-time student and, if he can't keep a job, a full time job. I'm terrified that it's all going to fall apart if I don't do something.