All of the symptoms you describe can be caused by Finasteride. Unfortunately if you experienced them after only a week, you may not be a good candidate for the medication and should consider quitting.
The FDA approval studies showed that of the men taking finasteride, around 5% had at least one side effect shortly after starting. However, after 5 years, only 0.3% still had side effects. This shows that side effects lessen over time.
From what i've seen, side effects are worst at the start, but get better over time. This is probably due to a period of your body adjusting to the changes in hormones. However, it's ultimately up to you if you want to try waiting it out, as there is a chance the side effects wont go away no matter how long you take it.
This is purely anecdotal, but I saw posted on another forum that if you stagger your introduction to the medication over the course of a few months, your body is more slowly introduced to the hormonal changes and people have reported that side effects are less severe or non existant all together. You would do this by coming off the medication entirely for a couple weeks, then taking 1 pill once a week for 2 weeks, then 2 pills a week for 2 weeks, then 3 pills a week for 2 weeks and so on until you are on it 7 days a week.
Best of luck.
Any advice would be greatly appreciated.