I've been diagnosed with fibromyalgia and osteoarthritis, but am developing more and more other little issues. could there be something more going on?

Possibly.: Fibromyalgia is is often if not always associated with depression which can manifest as a variety of symptoms such as poor sleep, fatigue, irritability, multiple aches and pains, lack of motivation, memory problems even anxiety. So, please see your doctor so you can discuss these problems and get appropriate treatment or referrals.

Most likely, yes: Chronic pain syndromes in this day and age benefit from re-evaluations from time to time. Fibromyalgia appears often to be diagnosed in individuals who have other causes for pain, such as small fibre neuropathy, various vitamin deficiencies (especially D), presence of environmental toxins, hereditary disorders (amyloid). Get all of this updated. Hope this helps

Many Possibilities: Depending on how long it's been going on, i would consider an evaluation by a spine specialist. Sometimes it could be a muscle imbalance, early onset arthritis or scoliosis. Also could be a pinched nerve/herniated disc. Either way it might be good to figure it out and get appropriate treatment.