The thing is with XT engines, especially a 2006 model, they are very basic engines and require little or no maintenance. For an engine as modern as yours to blow it is unheard of, Yamaha engines especially are known for being bullet proof and lasting forever. For your engine to blow or whatever happened to it, the guy who had it before you must of never put oil in it or serviced it. I know it seems like everything's going wrong at the minute, but you will eventually get it all sorted and you won't look back. It will make it even more rewarding. I have had countless fuck ups as well, When I first got my bike I got ripped off by a garage, my speedo has fucked up, now I need new brake discs, I've gone through 3 sets of brake pads, a new clutch cable, chain and sprocket, bought a new battery that I didn't even need, new front tyre, and other shit I can't remember. Welcome to the world of motorbikes.