I'm not Christian at all but I've read the Bible (various versions of it, plus the apocryph gospels) and as far as I remember, I don't recall any passage of Jesus blaming anyone because they were born wrong. Because as your grandmother says, those things just happen.
In fact, you see Christ actually helping them to recover from their defects. He cures a blind, a crippled, and such. Think of it this way. He's not alive now to be able to go to your home and give you the T now, but he has already sent you a sign making you aware that there is a medical relief for your problem. You're not going to hell just by following the steps he has been showing you.
I agree with John that you may be using your religious concerns to keep you away from yourself. I know it's easier to "let God decide for us", but sometimes God just let you to decide. You can think of it as privilege, as a test, or whatever you want. It's scary to understand that sometimes you have to act on your own, but it's the truth. Going by your own you can make mistakes of course, you're human, you're not perfect. But remember, you're not going to hell because of a mistake, but lying to yourself or using the name of God because you're afraid of yourself... well that's other thing. God is there to comfort you, not to be afraid of him/her/whatever.
I suggest you to sit alone, wether a silent church, your bedroom, or any place you feel comfortable and without distraction, do your regular prays and after that, just think about you. Leave God rest for a few minutes(well even he got tired and had to rest the sunday right?) and think what do you want for yourself, in your life. I encourage you to know yourself better before keep walking or using religion as a excuse.
What God is supposed to tell us is to follow our hearts, not our heads. If your heart is telling you to take T, then do it. But your head must be pure of doubts before it.