Ask for a second opinion. Your spinal column is narrowing creating pinch points on some nerves running through the channel. You are obviously feeling pain, otherwise they would not have ordered an MRI.
Google the terms and it will help with some of your anxiety. They are basic anatomy terms that describe a size reduction in a defect and where it is licated. The narrowing is describing space between T7 and T8. T = Thoracic. The thoracic spine starts at the knot where your neck joins the back. That is T-1 and as you move down the numbers increase. Until you hit the lumbar region where your spine curves in towards your belly.
Surgery has benefits and risks. Ask what those are. Only you can decide what is best for you. Your age, general health, gender, occupation, marital ststus, social status, and other factors play into the decision. Some of those factors only you know, unless your doctor hears about the from you. I have declined surgery in the past when the risks were not worth the benefits. Other times when a doctor wanted to delay a surgery and wait and see, the risks of waiting did not fit with my lifestyle at the time. Surgery now, plus recovery, and I am back on time the field in time for the season. Wait and I could miss this season and the next.
You are always the final decider in your medical care. The doctor gives advice and proposes treatment plans. You make the decision and did the doctor does what you want. Many doctors think it is the other way around, but once you assert yourself, they will respect your decision. They may not like it, but it is yours to make.