Good Day! By age 24 you should have fully developed secondary male characteristics (pubic hair, voice changes, penile enlargement). I am suspecting you may have hormonal
abnormalities thats why your penis did not develop and may also be the reason why are a bigboy( low in testosterone
may also increase chances of being obese). I would suggest seeing a urologist
or an endocrinologist
to have a compete hormonal work-up.