Lots of great suggestions. For arthritis: ask for help. By that I mean our unseen spirit family. Years ago I had growths on my finger joints and knuckles. I was upset. With the many years working on myself, on my spiritual path, this did not fit. I said, "I ask to be healed of this," and went to sleep. The next morning the growths, pain and stiffness were gone. A short time later I became quite angry with a coworker and noticed that night the growths were back. I knew why. My body stored my anger at the usual places! So I didn't ask for help again. Months later, I noticed my hands were fine. I gave thanks and they are fine ten odd years later. I know this is way out, but in case you are open to such. I don't know about you, but I'll take all the *unconditional* help I can get.
The stone that came to me for you was first ocean jasper, funny because you have had success with it! If the results happen for a short time, that stone and the blue lace agate may be showing you a doorway. Rather than stop using them, ask "What's next?" (They may need a helper stone if they are small. Maybe a quartz crystal beneath or beside your bed. We humans are much larger than we appear.
) Ocean jasper is also called orbicular jasper, due to a dispute over the name ocean jasper. I have two spheres of it, one who really enjoys dreaming with me. Maybe yours could help you stay asleep longer too?
Next my rutilated quartz sphere came to mind. I had major back surgery years ago and in my long path to healing, my "crystal ball" has been my main helper. It's silver rutilated. I sleep with it between my legs and it rolls just fine as I turn to sleep on either side. (I cannot sleep on my stomach anymore due to the back injury.) I wake up feeling like a new man. No matter how many times this happens, I am astounded and thank "Ruti" for the umpteenth time. My other spheres sleep with me too, but Ruti is the main man for bodily repair during sleep. If I would have known what a major part such a sphere could play, I would have put it out there specifically for a sphere that would sleep with me nightly. Ruti is around 3 3/4 inches/9.5 cm in diameter. If a large sphere offers to help you, that might be what you need. Back healing takes a lot of horsepower, in my experience.
For staying asleep, snowflake obsidian has helped many people with nightmares. It came to mind for you too. Stones are not one trick ponies, after all. I saw two pretty polished snowflake obsidian free forms the other day. I always leave them for others, but someday I'll meet one for home. (Trust me: I asked! ha!) Selenite just offered without explanation. I've slept with a large, clear piece beneath my bed for years now.
Do you have any larger stones? Or you can also ask the rest of your stones to work together. Ask them to hold your body as you sleep. Then you can enjoy your dreams knowing your body is safe and sound. I've dreamed between two cut amethyst geodes, large crystals, surrounded, etc. They can work from wherever they are in the house too. Ask stones around your house/neighborhood to help if you need to. Do you have a stone wall? Stonework in your house? A granite countertop? They can all anchor you while you dream. And the rest of your neighbors as well. Stones are strong! They go so long ignored, yet stand ready to help.
Finally, have you asked yourself to sleep longer? We can easily change sleep habits that way. I've changed physical habits while I sleep as well, like checking for my cat as she slept beside me, before turning. That all while asleep.
Trust yourself. If you are asking, you must be ready. Good journey!