Welcome to the GERD forum. We're just patients here, but we do care and will share our experiences.
It's just awful to have to wait. I waited 4 months for an appt with rheumatologist, 4 months when I needed surgery for stomach pushed into my chest in an accident, currently waiting 6 weeks for sinus surgery for pain and infection I've had for nearly 2 years.
Lymph nodes can be swollen if you get a cold or all sorts of things. Low back pain is very common, may be related to other symptoms or not. You can google it on the net and try to figure out what corresponds to your particular symptoms. I think I'd take it easy in the gym, try ice, heat, all the things I read on credible websites.
The stomach spasms could even be heart, not to worry you, but keeping a diary/journal of your symptoms might help you and your doctor figure out where it is exactly and what is triggering it. For me it was certain foods which contain large amounts of sulfite, but people react to MSG, lactose, wheat, and much more. An allergist helped me figure out my particular intolerances. My GI doc was good at diagnosing GERD, but still doesn't believe me about
the intolerances, even though I was able to control the refluxing by avoiding certain foods.