Park your van in a different location every few days. You'll want to keep away from law enforcement that might tend to view your domestic situation as vagrancy.
Save as much money as you can by shopping at discount food markets. You may be surprised to find that deep discounts are available at these venues, giving you the extra income to improve your current van living situation.
Park your van in a shady area whenever possible to elude sun damage throughout the day. A van can get rather hot in the summer months.
Park near a body of swiftly moving water if at all possible. This provides you with a ready source to wash cooking and eating utensils.
Find inexpensive campgrounds that provide water and electricity. This money saver can allow you to live in your van and not feel depressed by unattractive physical surroundings.
Remember to remain optimistic throughout this period and try to not worry about plush living accommodations. This is merely a temporary step to give you a chance to get back on your feet.