Yes I wish I started sooner with finasteride as well. Start off with low dose of finasteride 0,25 mg and see how you feel. Go from there.
If you feel bad or sides, try different brands of finasteride.
For me personally, finasteride made from my local apothecary is not only much cheaper but works much better for me mentally and efficacy than the official propecia brand.
With fin everybody gets a different response. General consensus is in the beginning it will raise your T levels because there's more leftover since the conversion to DHT is blocked. In longterm most say T levels drop again.
For me atleast I feel like since using fin ironically my body looks more manly, I'm constantly shredded don't put on any fat.Also I'm much more emotionally stable. Maybe it is cause my hormonal profile actually got stabilized by fin, in a good way.
Therefore it would make sense to get a hormone level check before starting out with fin. Especially when you fear sides, otherwise you'll never know what you natural baseline was.