We have a 10-year-old Murraya / orange jessamine that we bought from a Home Depot outdoor garden centre but have been keeping indoors as a house plant. For many years it did wonderfully, lush foliage and blooming profusely twice a year, but the last couple of years it's been struggling. I'm hoping to save it before it dies.

It's been slowly dropping leaves - sometimes, though not always, yellowing first. Twigs keep dying. The soil never seems to dry out anymore. Thinking perhaps it had exhausted its soil nutrients and/or the soil had become compacted - it had only been repotted once in the 10 years we've had it - a few weeks ago I repotted it and replaced as much of the soil as I could, cleaning out the root ball even, and pruned back all the dead twigs. Since lots of little rootlets got broken during this process I was expecting it to have a period of slight shock, but I think I might've just made the problem worse, as leaf drop/dying twigs has accelerated.

Is there anything I can do to save it? It currently lives at our patio door, which faces northwest. It likely gets drafts when we come and go from the door, but there are limited options for light in our house, especially for a plant this large. We do have a southeastern bay window but we removed all our plants from there when we were babyproofing. However, we did have it outside for the summer, and that didn't seem to improve its health, so I don't know. The decline in health might coincide with us moving into this house... or it might be coincidental timing. Could it be low light? Dry air? Cold drafts? Senescence?

Photos attached (sorry for the terrible quality; I only got a chance to do this after baby went to bed).