3 mi North? Belizean Shores or so? I would take the water taxi back and forth -- convenient. Walking south of town is far easier and better lit for walking at night -- not so much in the north.
In addition to eating at the best restaurants in San Pedro, consider having your kitchen (if you have one) stocked before you arive with essentials so you don't eat-out for each and every meal. Try
www.belizegrocery.com for details. The guy who runs this service is wonderful and offers a great service.