Based on the history (no calcium supplements, and essentially no UV) it would suggest metabolic bone disease/secondary nutritional hyperparathyroidism.
however, I wouldn't think the lumps would come up so rapidly if this were the case. Basically when a rapidly growing reptile has insufficient calcium, they will draw it out of their skeleton (e.g. jaw, limbs) to support normal bodily functions (Calcium is required for muscle contractions (amongst other things), including the heart- zero calcium = dead animal). Because there is less calcium/mineralisation of the skeleton, the body replaces this with fibrous tissue, which is less dense than bone, and the large quantities of fibrous tissue forms the hard masses. Now, I would imagine this would take more than a few days to turn up, as the fibrocytes (cells that produce fibrous tissue) would take longer than this to produce that much fibrous tissue. This definitely didn't occur over a week/a number of weeks?
Feel free to correct me... but it looks and sounds like MBD, except for the timeframe- its the only bit that doesn't make sense to me.
if it is in fact MBD, based on the size of the lumps, its fairly advanced, and would do best with veterinary treatment to rapidly replenish the calcium. So I would STRONGLY advise you to try your best to seek veterinary attention, whether you pay it over time or whatever- consult the veterinarian/clinic to see how they can help. In the mean time- buy a 10.0 UVB bulb, and rig it up ASAP. Take him outside for regular sunlight (but ensure he does not overheat) and get lots of calcium supplements into him.
Again-anyone- feel free to correct me.