No answers but I have similar issues in the T4-T6 and T12-L1. At first, I just had muscle spasms and pain wrapping around the chest; but lately, I've developed tingling and now the sharp nerve pain. I have been referred to a physiatrist so I know an MRI is in my future. My aunt has had 5-7 levels of her thoracic spine fused. I have a 3 year old so I can relate to your situation.

I haven't had epidural shots in the thoracic spine but have had the shots on the cervical and lumbar spine. In both cases, the shots brought relief. I have tried chiropractor help (6 plus years now) but haven't had success with that lately. I started seeing a naturopath earlier this year who takes a whole body approach rather than addressing one specific segment that has helped me tremendously when I'm having the flares.

Your arm pins/numbness/tingling: Maybe a cervical issue or peripheral issues - Do you notice a specific distribution?