Lower back pain between ribcage and pelvis right side, spot tender to touch, radiating to buttock and leg hot patch made it worse, what could this be?

Many things. It could be caused by a herniated disc, spinal arthritis, something called spinal stenosis or a list of other things. As always, it is difficult to say what is causing a patients pain without seeing them in person. I would simply admonish you to see your doctor if it is really bothering you.
Muscular. Self or profess massage, chiropractor, yoga, heat, stretching all are needed. My favorite in my practice is acupuncture and myofascial tissue release. Be careful some docs will place the blame in you disc and advise surgery or epidurals .... No!
Might be shingles. It depends on how long you've had these symptoms. If it's just been a day or two, watch for blisters or a red rash in the area. Early shingles will cause a burning pain in the involved area of skin before the rash comes out. If the pain has been there a while and radiating from back to buttlock you might be having muscle spasm, a pinched nerve, or even a kidney stone. See your doc.