Pin head black spot

I am really worried about a pin head black or dark red spot that seems to be part of the side of my tongue I have a dry mouth and my tongue feels,rough although I try and drink lots of water I am due to go to the dentist as I have toothache lower bottom right back teeth . I cannot get a suitable toothpaste that helps me with sensitivity. As I cannot get Sensodyne classic origiginal toothpaste. I ordered online from Amazon and they sent me some but I don't think it is the original classic toothpaste . Other than that I keep googling this black pin head spot and it says mouth cancer. It seems I get one thing after the other and worry . Thanks any advice would be appreciated most toothpaste have fluoride which makes my mouth burn.