Realistic odds are that you will face more chance of danger getting to the trailhead for your trip from home than you will on the actual trip.
A good walking stick is always of use- I have diverted a number of snakes from my path over the years with one. If you carry a bear spray canister, you will be about as well protected as possible against 4 legged predators.
The 357 mag revolver is another very good recommendation, IF it is legal to carry and IF you are proficient with it.
(Mostly for 2 legged predators.)
I think though that you have let a few incidents stir your imagination into overdrive. I would rather walk 20 miles unarmed in the woods than I would 2 blocks in the inner city.
As others have pointed out in another recent thread, your best defense is your situational awareness. Don't be oblivious of possible danger signs, remain alert at all times, and you can avoid 99.99% of all problems.