Can’t fully open jaw after small filling

Almost three weeks ago I got a small filling in my lower right molar. I was immediately sore after the numbing wore off but figured it was normal (I’ve only ever had two fillings before this). I realized after day two that I was still sore and worsening so it probably wasn’t normal. I can’t open my jaw fully to eat and moving it to the left and forward is also painful. The pain is localized to my right jaw muscle, not necessarily the joint. I went back to my dentist a week after the fill and he suggested doing stretches as well as taking prescribed muscle relaxers. Unfortunately, I cannot take muscle relaxers due to another med I take for migraines - so I’ve just been taking ibuprofen. He did say that a nerve could be aggravated or the jaw muscle could irritated from being open so wide for the cavity fill but things should have calmed down by now.
It is very painful to do the suggested stretches and I physically have to force my jaw open and to the side with my fingers. It is an incredibly unfun experience that has brought me to tears at times. I think the stretches are only helping a little, I can open a bit wider than I could a week ago but it’s still impossible to eat a sandwich or things that aren’t cut up.
I don’t have a history of clenching or grinding and this kind of thing has never happened with previous cavity fills. I feel very defeated by this as it’s starting to affect my day to day life. I’m unsure on how to move forward or what could even be happening.