multiplayer Mathematics game need to be transformed from shared hosting to handle thousands of users -- 2

I have a php javascript mysql math multiplayer game that can be played by 5 or 6 at the same time. The problem is : it is hosted by shared hosting, so many people cannot play at the same time as it cannot handle database access. Is there a possibility of involving node.js or socket.io or both. If you suggest going for different type of hosting i will consider. Something like world maths day games where millions play at the same time. Are you good at that? Please advise. What is the cost? please kindly read this before bidding. math-ib.com---> login : usr principal pw: 123 ----> world arithmetic game-----> create game--> register---> start ----> join