funny taste & smell? not covid!

hey y’all. two days ago i ate something and noticed it tasted a little off. didn’t think much of it and went about my day. the next day i noticed things tasting odd three different times. it happened again last night/this morning. additionally, everything either has an old ketchup smell or the smell of something burning in the toaster but like the inside mechanical part of the appliance…

i took a covid test to rule it out and it was negative. any other thoughts?? i want to eat like normal but everything is just so gross smelling and tasting