What do you mean by “blind” in reference to faith? I would say that faith is something which enables us to know God, and thus it is not blind, but actually illuminating–it helps us to see the Truth.
No one can tell you what you can or can’t feel, but remember that feelings don’t determine the truth. If you feel guilty or ashamed, step back and ask yourself what is really true. Instead of identifying with being gay, since that isn’t the whole of your reality, remember that you are created in the image of God and much beloved by him. That is the only identity you should ever concern yourself with. Guilt is something that we experience or know positively in response to having done something wrong–it isn’t just something we feel, it’s something we can look to and say “I have done something wrong, therefore I am guilty,” or “I have not done something wrong, therefore I am not guilty.” Having a same-sex attraction carries a lot of emotional baggage, social stigma, and pressure to conform, and this can create a lot of feelings of guilt and shame. But in reality, if you know who you are and what you are called to as a child of God, and you don’t act upon inclinations which will lead you away from him, then it doesn’t matter what baggage or stigma or pressure there is. All that matters is living in the truth.
As for the second question, we start with God. We can know there is a God by reason, and see that there’s an order to how he put all things together. From there we can also see that not everything conforms to that order, it’s somehow broken or distorted at times. So there must have been something that broke it–it can’t be God, since he created it. Man distorted it by sin. So God, being as he loved us enough to create us–for love is to will the good of another, and it is better to exist than not to exist, and so it is an act of love to create–and so he would not allow us to be destroyed by sin. And furthermore, God created us with reason and will and intellect so that we might know the truth and choose the good, and he himself is truth and goodness, and so he would also not allow sin to stand between us and what he created us for, himself.
So he became man, died on the Cross, rose from the dead, and raised up our human nature to union with him. He left behind a Church as the sign of his saving presence in the world until he returns, and appointed an authority to safeguard the means of grace he had given.
God loves us enough to have done that. That’s how we know it’s all true.
-Fr ACEGC