"Structural incompatibility"...?
Not trying to be sarcastic but testes and a vagina seem likely to interfere with each other; it's really one or the other (we will ignore the ethics of the surgeon here). A "true" hermaphrodite is a VERY rare physical condition.
OTOH, from my experience I can attest that Estradiol does reduce male libido, of course at age 66 it was already pretty low. An orchiectomy or anti-androgens will reduce libido regardless of age. Performance aids like Viagra or injectables are a different issue.
HOWEVER, you MUST see a reputable medical professional to have a consultation / evaluation and decide, in your own mind, whether you want to transition or not (and how far you will go).
Above all be safe,
Sandra1746