Welcome to Excelmale.
*Your lab results are incomplete. Was any effort made to check your LH and FSH? Was a full thyroid panel run?
*Those results posted certainly point toward hypogonadism, and I can't help but wonder if the finasteride that you've taken for 15 years (!!!) hasn't played a role in the onset of your erectile dysfunction. It's a drug that doctors on the leading edge of androgen replacement in North America will not prescribe due to the severe side-effect profile that it has. That said, some men certainly tolerate it, you seemed to, but has it caught up with you? Was the combination of dutasteride and finasteride enough to impact your endocrine system. This article paints a strong picture of what this class of drug can do in terms of male sexuality and depression.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4064044/
*Your depression and anxiety certainly can be contributing to your erectile issues. Have you discussed these issues recently with a therapist? The strong fear of losing your hair both occupies your mind and blocks you from considering other options. That's your choice, but have you looked at your health in a broader perspective at this point?
*Why is starting TRT something you "can't stomach?" That's a strong statement for a program that has restored the health of so many men? I can understand your wanting to avoid it if at all possible, it seems you're seeing it as a sentence of doom.
*An improved diet and exercise is certainly an excellent idea, whether it improves your androgen levels or not. So is a good night of sleep. Are you sleeping well? What other drugs and supplements are you taking?