Hi aquaholical and welcome!
Sorry to hear about your problems and it's good that you are asking questions and trying to find out what's wrong...
I believe everything in the body is connected and it's possible that when you injured your spine it could have weakened your immune system bringing out the lyme bacteria (since you mentioned that you were bit by a tick and had the bulleye's rash even though it was 19 years ago). I believe that lyme bacteria can lay dormant for years and years and show no symptoms until either a stressful event occurs whether it's physical or emotional.
No lab is 100% accurate but the closest we come is IgeneX and you can order a free test kit at their site: www.igenex.com Please don't waste your time with labcorp or quest because they use rat's blood instead of human blood and not enough strains.
You will need a doctor's signature to get your blood tested at IgeneX and at least that would be a good start.
If your body is telling you to rest, then please rest and don't push yourself. Lyme is extremely treatable though what works for one person may not work for another. You have treatment options if you do have lyme.
I hope this helps and that you start getting some answers. I know how frustrating it is to search for those answers... Been there..
Hang in there,
Denise