Painful Composite Filling

[beautynbrushstrokes]

Hi, a few weeks ago I had a composite filling fall out on my very last tooth on my right side. Thankfully my doctor was able to get me in a redo the filling but since then the tooth has been incredibly sensitive. Also I've noticed a very metallic/bloody taste from that tooth. Should I be worried, its been a few weeks? Could this be a sign of a bigger problem or is it just because it was a really deep filling?

Any advice would be great.