While I am still young, I have a hip injury (femoral acetabullar impingement) that makes getting up difficult and painful. Luckily, I have a sister who is an occupational therapy assistant. (Her job is to help people relearn ways to do activities of daily living, such as getting up, ambulating or using devices to make things easier). Her suggestion for getting back up from sitting on the ground is to roll on my side and then push up. Sitting on something like a chair is probably a good idea for you. You may want to see if you can consult someone like an occupational therapist to get some ideas to help you.
For the hitch as others have said, the Anderson is lighter weight or you can get something like the propride. You can also ask for help at the campground. I know we are always glad to help people out (that way we can pay it forward for all the help we have received too). A thank you is all I ask... DH does like a beer though
. Good luck to you and be careful.