Load js scrips on component variable already in use

Question

I have an angular app, and one component has to load some javascript files from assets. These scripts are loading some data into some graphs on my component page. When I click on a point on the graph, I get redirected to another component.

This is how I am loading the scripts:

loadAPI: Promise<any>;

  constructor(private router: Router,
    private route: ActivatedRoute,
    private communicationService: ComunicationService
  ) {
    this.route.params.subscribe(params => {
      this.name = params["name"];
      communicationService.emitToolbarNameChange("myPage");
    });
    this.loadAPI = new Promise((resolve) => {
      this.loadScript1();
      resolve(true);
    });
  }

public loadScript1() {
      var isFound = false;
      var scripts = document.getElementsByTagName("script")
      for (var i = 0; i < scripts.length; ++i) {
          if (scripts[i].getAttribute('src') != null && scripts[i].getAttribute('src').includes("loader")) {
              isFound = true;
          }
      }

      if (!isFound) {
          var dynamicScripts = ["../../../../assets/js/main.js","../../../../assets/js/1.js","../../../../assets/js/2.js",
        "../../../../assets/js/3.js","../../../../assets/js/4.js","../../../../assets/js/5.js",
      "../../../../assets/js/6.js","../../../../assets/js/7.js","../../../../assets/js/8.js","../../../../assets/js/9.js"];

          for (var i = 0; i < dynamicScripts.length; i++) {
              let node = document.createElement('script');
              node.src = dynamicScripts [i];
              node.type = 'text/javascript';
              node.async = false;
              node.charset = 'utf-8';
              document.getElementsByTagName('head')[0].appendChild(node);
          }

      }
    }

The problem is I have to define the variables as var's in the js files, I believe they are overwritten each time I access the component page. If I have them as let, they work one time then I get errors in the console that they are already used.

If I load the scripts in the index.html or in build { ..., scripts []} no data is shown on the page. I am redirecting from my component page and from that page back to the component page.

Any suggestions on how to load the scripts?