Is is TESTOSTERONE or DOPAMINE ?

I am 28 years old dude, I am suffering from ed and pied.
I did a blood test regarding my testosterone levels , Because I was flatlinin for almost 3 months and I thought my lack of libido might be related to low testosterone.

So my total testosterone came - 620 ng/dl
My free testosterone came - 20 pg/ml

I searched google, and it says these levels are normal. So I guess now I am conviced its not testosterone related problem but rather dopamine and dopamine receptors related.
Any one can suggest something else?