It's not clear why you wouldn't have checked out the neighborhood before deciding to rent there.
"We recently detered a group of 4 late teen / early 20 year old from breaking into the house and because of that I now fear for my safety while in my house, since they know where we live."This is a bit confusing, since presumably they knew someone lived there beforehand ... and it's more likely than not that they won't be back if you can identify them. Taking stuff (and dogs are technically property), attempting to take stuff and vandalizing doesn't indicate anyone wants to harm you physically.
If you break your lease, the landlord has to mitigate/lessen its damages by re-renting as soon as possible. That it would take many months is unlikely, and you're free to place your own ads in the paper and document referral of interested people to the landlord.