You are right your right temple is alarming. Based on just that, I would have said that you had definite early signs of Androgenetic Alopecia but your left temple is not showing similar recession pattern; usually, Androgenetic Alopecia follows a balanced pattern. You are also seeing thin hair falling off, so I am thinking you are right to be worried.
However, you took the plunge too soon on finasteride. You first needed to confirm that you had Androgenetic Alopecia.
This is what you need to do asap
A) See a Derm experienced in hair issues. Let him run a test or two. I think they have some magnifying lens screening tests that look for miniaturizing hair on scalp. Once confirmed then continue with finasteride if you want to dedicate yourself to it.
B) If not that, I would gauge my hairline recession. You will need a magnifying mirror, a table lamp with a 75-100 watt bulb, and a measurement tape. Measure your hairline all over from, lets say, eyebrows, or in relation to sideburns etc, and make a note of it and note how it looks in terms of density etc. and do that as frequently as think you need to.
You will know when it further recedes within a certain time period. I would not have started finasteride yet until confirmed; if its not Androgenetic Alopecia, then you might be hooked to finasteride unnecessarily.
Regardless, even if you receded a little bit more without any treatments, and then started treatments later; I think you would still be fine with hair volume-You will know before it gets too bad; and finasteride. hopefully would have regrown some anyway or you would still have had plenty that you could be happy with. Some recession in temples does not look bad at all
Good luck!