40 days into sciatica recovery and suddenly back to square one?

A little context: I’ve been dealing with sciatica for about 40 days. During the first week, the pain was around 8/10, so I saw an orthopedic doctor and started treatment with NSAIDs and rest. I haven’t had an MRI yet.

For the next ~25 days, things were actually going pretty well. I was seeing slow but consistent improvement, and eventually the pain was down to around 2/10. My doctor then introduced some gentle exercises.

I started the exercises a few days ago. During the exercises themselves, I felt no pain at all. A couple of hours afterward, though, my symptoms would increase slightly. I assumed this was probably normal given how much rest I’d had, so I decided to reduce both the intensity and the number of repetitions to avoid aggravating anything.

That seemed to work. I was doing fine for about 4 days.

Then today, completely out of nowhere, I woke up in extreme pain. I can barely walk or stand, and the pain feels like an 11/10. What’s especially concerning is that I now have a new pain sensation around my big toe and the front of my calf, which I didn’t have at the beginning.

I’m honestly really confused and frustrated. I thought I was finally on the right track and making good progress. I haven’t done anything unusual, lifted anything, or changed my routine. Everything has been basically the same.

Has anyone experienced a sudden flare like this after several weeks of improvement? Can a flare suddenly become this severe even without doing anything obviously wrong? And does the appearance of new pain in the big toe/front of the calf mean anything different?

I’m planning to see a new doctor and order an MRI but till then wouod appreciate any advise.