@lostintheabyss18,
The idea with relationships is that we learn from them, good and bad.
Time for you to take an individual step or two.
Don't see your girlfriend tonight. Go for a coffee, read a newspaper/magazine/book, greet other people at the place you're having coffee. Go home.
Go to a gym. Work out for an hour. Play a sport. Something. Go home.
Your girlfriend may blow up just from that. Deal with it. Be cool/calm. Let her know you needed an hour or two to yourself after work. Ask her if she'd like to join you for a coffee out tomorrow or Friday.
Take control of the situation.
Maybe you'll break up. Maybe she'll smarten up and stop being so possessive and paranoid. Maybe you'll make new friends.
In the situation you described so far almost any change would be a good thing.