Ok, Marty. you convinced me you've come from the future back to May, 2008, but I can't help you get back to the future.
Your time machine needs intense heat to activate the time circuits, and in 2008, we can only do that with a volcanic eruption or a huge fire or something.
I'm an ethical scientist, and I will not commit arson to get you back. And otherwise, you never know when a big fire will break out.
We do now. Look at this podcast: 30th anniversary of fire that destroyed clock tower set at Universal Studios ...