Keeps flickering between "Play Offline" and "Play"

Hey hey! I decided to try boot up my Minecraft to play with some friends, and when I had opened the launcher I discovered that It was flickering from Offline and Online mode. I launched anyway, and It told me my game session was invalid.

I followed the steps, looked at other posts and nothing seemed to work. I even fully disconnect my Internet and restarted my computer, and then reconnected and tried again. Any clues what could be the issue? It was fine just last month.