How important are reference letters?

This might be a stupid question, but how important are the quality/content of the reference letters? I know they must be fairly important like anything else we have to submit, but still. I'm literally freaking out about it because I cannot name three people at my uni who could write it for me. The best I could do is just email my profs/past profs and just beg them to write a letter that says I got excellent mark in the class and literally nothing else because no one knows anything about me. I'll ask my topic supervisor which will be at least 1 good letter, but the others I'm totally lost.

Otherwise I think/hope I could stand some chance (at least worth the time and money to submit the application). I'd apply for Msc in Physics/Applied Physics. I have 4.65/5 GPA, in my country we have a competition where we present our papers for which I've written one, I presented my poster at a conference and I've spent both of my summers in research internships. I've had some little projects, I participated in a research summer camp. I feel like I’ve made the most of the opportunities I’ve had. But about reference letters I'm freaking out.

Any thoughts, suggestions?