haha, you'll be fine Dex!
Be Oaf, I must preface, i'm a relatively new member, and I am not an expert, however I feel I've acquired a modest foundation from Spencer's weekly radio show in this time (you can find it on this site), and I would really advise his show if you are looking for objective advice, or like me you may also find it therapeutic.
I will assume that you haven't read up on finasteride for the purpose of my explanation. The drugs pharmacological action (correct me if i'm wrong) is by inhibiting the enzyme which converts testosterone to dihydrotestosterone (DHT). DHT is a hormone, with roles in libido and erectile function (and others), and is found to be a primary contributing factor in mens hairloss when combined with MPB gene. So, finasteride lowers DHT, thus preventing its negative effect on hair follicles.
You may or may not know that the dose-response curve of finasteride is "flat" after a dose of around 0.2mg, meaning that the inhibition of DHT from a dose of 0.2mg-5mg is negligible (ranging from ~60%-70% inhibition range dependent on dose). I can't find the graph right now but it might benefit you to find that.
From a subjective point of view, everyone's testosterone and DHT levels vary, and unfortunately (due to a lack of drug personalisation and perhaps research) finasteride cannot promise a one size fits all, as a 70% fall in DHT could drastically differ from you to me, if you catch my drift.
The number of reported "side effects" with finasteride are a very small minority (I don't have the percentages at hand), and my personal (perhaps controversial) opinion as a scientist myself, is that the majority of those even are perhaps psychosomatic. I should mention that these "sides" relate to a reduction in DHT's normal function in the roles I mentioned above.
Now, I feel this specifically relates to you. There has been speculation from several guys on the forum that incidence of reported side effects MAY be correlating with those with slowly progressing hair loss (i.e. those with marginally high DHT levels above norm that are killing their DHT levels by an unnecessary 70% with finasteride).
(I need someone with more knowledge here). Due to the half-life of finasteride, and it's pharmacological effect on DHT, many recommend a lower dose than 1mg/day, and many are now also advocating an intermittent dose, such as every other day, or every 3-4 days for example, rather than daily. But if you read what I said, a dose of 0.2mg will have a very similar inhibitory effect on DHT as a dose such as 1mg, and here stands the problem, though it's important to note that much more side effects are reported at higher dose (they aren't sure exactly why - perhaps that 5-10% more inhibition made all the difference to healthy function).
It is recommended that you request test/DHT levels done from your GP before you start taking finasteride, so that a later re-test can allow you to monitor the effect finasteride has had on you PERSONALLY, thereby personalising the drug.
My personal advice would be to (in accordance with your GP), try and be prescribed 1mg finasteride, so you can attempt to dose at 0.2mg or lower, perhaps every other day, for a few weeks or months as you monitor your reaction to the medication.
Failing all of the above, and if you take 1mb per day, you haven't had your test/DHT levels checked, IF you do experience any side effects, it is best to monitor them for a week or two before deciding whether to stop taking the drug, unless they get worse. This is due to the fact that they might pass and you may never experience them again. For what it's worth, I take 0.5mg daily, I had dull ache's in my testicles for the first week and then it subsided.
I apologise for the lengthy message, and I hope you can gain something from it.