Freaking out about whether to shave my head or start finasteride. Help? I'm 26.

[MB8]

It's entirely your call but, if I were you, I'd start taking 1mg of finasteride each day.

I was the same. I noticed my hair thinning but I was too scared to take finasteride because of all the online horror stories I'd read.
In the end, I became so depressed about my hair loss that I decided to chance it. Now, my only regret is not starting sooner.

A few things, however.
Firstly, be consistent i.e. either take it or don't take it, but don't stop and start and stop and start. In my opinion, this is what really messes with your body. If you're going to take it, then get into a good routine.
Secondly, don't expect immediate results. It took me ten months to see any sort of improvement - you might be quicker or it might take you longer.
Thirdly, if you're going to take it, then you have to stop worrying about side effects. If you read the trial studies, you'll see that the number of patients who experienced side effects (the SAME side effects) was roughly the same for both the finasteride group and the placebo group. [On a personal note, when I started taking finasteride, I experienced a sort of dull ache in my right testicle. I reported this to my doctor, and he said it was nothing to be concerned about. Sure enough, within a few weeks it had disappeared. If you're worried about sides, have monthly check-ups with your doctor.]
Lastly, no-one can predict the future, but if you're going to take finasteride, then I think you have to accept that you'll be on it indefinitely (provided you still want to keep your hair, that is).

I'm not a doctor, so all of the above is based only on my personal experiences and opinions.
Whatever you do, I wish you all the best.