Gee, that sounds like an awful state to be in for 10 months. I don't blame you for wanting to quit.
You don't mention the dosage you are taking -- did the physician start you at the lowest dose and gradually work your way up, monitoring symptoms and side effects at each visit?
I know one 40-year-old lady who was started at an incredibly high dosage of Vyvanse and had the same kind of experience you describe -- but for a much shorter period.
The fact is, many physicians are just not careful in how they prescribe and monitor these medications. They fail to "start low, increase slow" and they also fail to monitor for the co-existing conditions that are common with adults who have ADHD. These conditions include depression and anxiety, both of which can be exacerbated by the stimulants.
Sometimes an additional medication will be needed.
I would also ask about your lifestyle habits. Are you drinking coffee? That is sometimes a lifelong habit for adults with ADHD, and they don't give it up when they start a stimulant. They should really consider giving it up, though, as it can interfere with the stimulants.
At age 45, you might also want to ask an informed physician about how perimenopause might be affecting you. You might want to read up on that topic (perimenopause) as well as nutritional supports you can pursue, such as starting the day with a protein breakfast, taking a multi-vitamin/mineral that includes B vitamins, and so forth.
best of luck to you!
Gina