You asked your parents about any extended family that might stutter? This is quite unusual, but not unheard of from what I know. It must be quite a shock and im sorry this happened. There are a lot of resources online and good material out there. Check out the NSA, www.westutter.org. They have an annual conference, this year it's in DC. Just remember that blocking is a problem of air flow. your vocal folds spasm and either lock in an open position (in the case of vowel sounds) or locked closed in the case of hard consonants. "trying hard" or pushing through is just creating a fight you generally dont want to do. Stutter is largely neurological and a miscommunication between the brain and speech producing muscles. But without brain trauma or something, i'm not sure. then again, im no expert. Have you ever seen a speech therapist? They can be very helpful, but only if you're able to find a good one that works right with you.