Can you re infect yourself with covid with a toothbrush you used when you had covid. i had covid last week and was feeling better now today feeling bad again?

Not from a toothbrush. Best is to get checked for cause. I hope you feel better

A bacterial infection can be transferred from a brush. Having COVID, your immune system will protect you with antibodies from reinfection from your toothbrush. In any case it is always best to use a new toothbrush after an infection, and never share a toothbrush.

Covid virus needs a host to thrive. It does not do well on surfaces outside the body. Bacteria, on the other hand, can thrive in a moist environment, such as toothbrush bristles. Always change your toothbrush after an infection. Get tested for Covid, but even if positive not from t'brush.