HELP black spots on tongue!!

Hi, I don't drink or smoke and eat relatively good. Over the past few years I've noticed little black spots come up on my tongue. It started to happen about 4 years ago since then I've had two babies so I've been pretty full on and didn't get much of a chance to have it checked out. I did remember going to the doctors once and she said it was possibly a bad case of thrush and gave some cream to put on my tongue (this didn't work, I've still got it two years later) I really don't know if it was some sort of medication that caused it or what but I am so self conscious about it. I feel like when people are talking to me they are looking at my tongue. My boyfriend who I've been with for two years has never seen my tongue that's how much I hate the spots. It just looks gross. And it's kind of spreading to the sides where the veins are. Any ideas on what it could be? Should I go to maybe a dermatologist or something?? HELP