Smooth, couple thoughts for you for another closeted guy...
"But for sure we've studied the human anatomy. Like I said before, a sperm is for ovum. not sperm for sperm. The anus is not a sex organ but a hole for excreting human waste."
Don't get too hung up on men are designed for women and vice versa, or body parts are for certain things. We use our hands for anything, women's breasts are 'for breastfeeding' but they also play a role in sex, just like a woman or man's anus. The pleasure centers of the whole body are found in more places than just penis and/or vagina. Why is the neck or ears involved in sex, or lips for that matter? Sex is a whole body thing, and whole mind thing. The argument that gay sex is wrong because of physiological design is just a daft argument asserted by people who want you to think it can't be ok. Sex being a mind/body/spirit thing goes way beyond anatomy. The anti-gay crowd wants to keep it simple, and if you accept that, they win.
"And why being in the closet always called a "LIAR"? Am I really LYING to myself and to others? "
You are right, you don't owe it to anyone to announce that you are bi/gay. Withholding the information isn't lying. Now, if someone asks if you gay or like guys, you say 'no' - that's lying. But just because a person asks you something, YOU DO NOT OWE THEM AN HONEST ANSWER.
In every situation you face in life you must use judgement about what and to whom you divulge truthful information about yourself or those under your charge. Lying is a social skill and not a fault. Bad judgement about who to lie to and why - that's a fault. You start learning it as soon as you start talking. You spend your entire childhood figuring out how to lie. The smarter your parents, the more challenging the lying and the better liar you become. Lying is work and it is more comfortable (skillful as atxclimber would say) to arrange your life so that you can be honest with everyone around you.
Also, just because you can and do lie to a person or whole group of people, does not mean you are incapable of being completely honest with someone whom you trust.
Lying is also NOT a malicious act. It can be, but it isn't inherently malicious. It gets a horrible reputation generally, because we spend the first 18 yrs being told by our parents 'Don't lie to me, young man! I know your lying, I wasn't born yesterday!' The underlying point to that situation being that parents don't want you to lie to them - because they are the ones you must trust to protect and guide you.
Don't come out, until you decide the chance to rebuild your life surrounded by friends who 'understand' you; family who can hear about your real personal life; and go public with a boyfriend anywhere - the chance to have that is worth the possible loss of family/friendship/occupation that you have developed to-date. If you live with Mom and Dad, can't afford an apartment,don't have any other living arrangement made and don't think they'd take it well, it's probably not a good time to come out. If the boss is a jerk or other gay's in the company don't advance, works not safe either.