My heart goes out to you - I completely understand what you're going through and struggling with.
I came from a very conservative christian family. At 20 I tried to come out to them, I was dealing with accepting myself and made the attempt to explain it to them and open up - but I was pre-empted with the "no son of mine...it will NOT be accepted" lecture. I retreated back into the closet, as far as family was concerned. There were many years of a strained relationship with my parents, and I should have come out completely to them when I tried and faced the consequence, but I didn't.
My father has now passed on, and I think he was ok with it, my mom is still around, and we just don't talk about "it." My sister is great and very accepting - my brother is "don't ask, don't tell."
My life with my family is far from how I would like it to be, but that is a result of my decision to not involve them in my personal life. I would not recommend taking my approach, but it seems too late for me to change it.
So, if you decide to tell them, don't back down or retreat - it may be messy and you may be estranged from them, but you will feel better about it.
If you don't tell them, then be prepared to always have a wall between you regarding your sexuality. I'm sure in time they will figure it out and deal with it by accepting or rejecting, but I think it's better to get it out in the open and be done with it.
The thing is, do it when you're really ready to, and be prepared to have your mind fucked up and be heartbroken, it's just a sad reality for many gay men.
(At one point my mom said she'd rather I was dead then to tell her I was gay - live with that all your life. I love her dearly, but things will never - NEVER - be the same.)