Rewriting my web application (PHP)

So I am writing a Web application for workouts and meal plans(i just need insert all the workouts in database and it will be done), I am using PHP and MySql for server side, and HTML, CSS, JS for front end. Application is really complex, database has more than 25 tables and a lot of complex statements, I have a lot of functions and few algorithms so every user would get different kind of workouts and food depending on his needs. I started writing this application in same time I started learning PHP so i wrote it in procedural PHP and everything is spaghetti code, and after a while It has come to my knowledge that I should use MVC architecture and OOP, or some kind of framework. So I want to know, should I rewrite it or just leave it like this for now? What are advantages of using framework in this kind of application, and is there a point in rewriting an application just because you are not satisfied with it? And what are scaling problems with procedural PHP, and are there any advantages in scaling with frameworks and OOP?

Thanks in advance