I already said this, but I'll say it again. I don't believe a follower of Christ has to take the whole OT and believe it. I mean, you have to believe in God, but as for the rest of it... I think you can let it rest.
Logically, Christ being the son of God, is easy. I can't speak for the OT, because I haven't studied, haven't really concerned myself with much of it. I was taught much of it as a child, but as an adult, I focus on Christ. Again, believing in Christ as the son of God, logically, is easy.
If you're trying to convince yourself that God does not exist, or that it's all hogwash, then I don't know what to tell you. All the pat answers, God works in mysterious ways, for everything there is a reason, etc. are there, for what it's worth. I've had some low lows, but I can see (now) how much I got from them, I can see that (as much as I disagreed at the time) it was not more than I could handle. I can see that I grew because of those times.
I'm not all sunshine lollipops and rainbows, but I do try to hand things over to God. I'm stiff necked by nature and it's HARD to give it up, it's hard not to cling onto the things I disagree with or want to change. All I can do is try, pray, read, trust. It's a shaky limb, putting all those eggs in one basket, but... I mean, it's God's basket, His limb, and if I can't trust Him, well that means I really am all alone. God won't FORCE me to trust Him. If I choose to be alone, then there's no one to blame, but myself.