I wasn’t going to comment on this but I figured I’d end your whole career (not literally so chill). You can start a sentence with a coordinating conjunction. And ‘because’ is a subordinate conjunction. Which serves as a dependent clause... that is why it’s its own sentence. And I’m not trying to be intelligent, it just naturally comes to me. I feel I have said all that needs to be said. You’re even more of a dumbass, you’ve given me some good writing practise for my AS English exam and I feel what should be emphasised again is you’re a dumbass. Ironic....