7 month old baby won’t eat solids

My 7 month old just won’t eat. He use to be good at eating and ate everything but since he has hit 7 months, I can’t even get a mouthful in. He keeps his mouth so shut so I can’t get a spoon in there at all! I know he might be teething, but he won’t eat Anything!!! He has 4 bottles 7oz a day, and SOMETIMES snacks on finger food. I’m scared that he’s not getting enough of what he needs, but no matter what I do I can’t feed him. I don’t want to force him to eat but he needs food. Has this happened to anyone else’s little one or going through it? And how can I help my baby eat