Here are your options:
1.) Move to another Walmart
2.) Move to another business that is boondocking friendly, including truck stops, Cracker Barrel, Cabela's, Camping World, and casinos
3.) Small towns tend to be less RV restrictive. Move to small town and park near a park or ball diamond with a large lot.
4.) Visit this website:
https://freecampsites.net/usa/
5.) Visit this website:
https://www.boondockerswelcome.com/all-boondocking-locations
6.) Join this website and ask those who are "couch surfing" friendly if they have a parking spot to park your RV:
www.couchsurfing.org
7.) Join Harvest Hosts, which has many free camping spots across the country:
https://harvesthosts.com/
8.) Park on a residential street w/24-hour parking in front of an abandoned property
9.) Industrial parks often have places where semi trucks can park. RVs can often blend in there too without a problem.
10.) Move to a well-lit rest stop
11.) Weigh stations often have room to park
12.) Post a request on Craigslist for help.
13.) You can often hide for 24 hours in a hotel parking lot if you come in late > 8 PM and leave by 8 AM.
14.) If all else fails visit this website:
http://www.rvparkreviews.com/ ...and find a cheap place to stay.
You make this way harder than it needs to be. Contrary to what Elvis might lead you to believe, there are MANY more options out there for boondocking and dry camping. Walmart is arguably one of the worst of the options. I, for example, am wintering in an aircraft hanger for $200/month, which includes all power, heat, shower, bathroom facilities, etc. That's only $6.67 per day.
If you are going to boondock you need to do your homework in advance. Even if you move to a new place and feel secure, you need to have a Plan B and a Plan C just in case. Google Maps w/aerial view and the links above can be your best friend. Then plot your options using Google My Maps or Google Earth.
Being a boondocker is a bit like being an explorer. You can't just sit back and let things happen to you, much like it seems you've allowed your entire life. You need to be proactive. You need to be a problem solver. On your own.