It sounds like you've been through quite an ordeal. You are fortunate, sometimes stories like yours can have terrible consequences, its nice to hear a good story once in awhile. We occasionally get people on here that have had fractures, but not a lot.
I've had back surgery and I have rods in screws in my low back, although their for a completely different reason than yours are, and I haven't had any problems with my hardware. Failures do happen, but there very rare and I wouldn't be to concerned about it.
As far as getting back to normal activity, you should be able too, and the fact that you don't have a lot of pain will definitely help. But its going to be gradual and it'll take time. P.T plays a very important role in this. Hopefully, you'll have a good Therapist, because they can make a big difference. It took me about 6 months to feel half way decent after surgery, and about a year to fully recover, but I had pretty serious nerve problems with my leg. I was your age when I had surgery.
I don't know about laying on your side, you're going to have to ask your Doctor about that. Its the only way I can sleep. Maybe someone else will see your post and add their thoughts.
Take Care
I hope you find someone to talk to. I would recommend supplementing your traditional care with some alternative care for the best outcome. Homeopathy would help as would energy work such as Reiki or something similar. They can't hurt and don't interfere with the traditional care.