Scrollable DIV in widget

Hi guys,

I’m using a fixed-height (110px) DIV within WordPress which I want to make scrollable using Javascript.
My website is at https://thinkrasta.com/home. The widget is the ‘Recent Tweets’ widget on the right sidebar.

https://pastebin.com/pQBvArQn: Here’s the PHP Code which also contains the Javascript (tweets-widget.php)

https://pastebin.com/1iXiA7Hy: The JS file (jtwt.js)

https://rocha.la/jQuery-slimScroll: The code and documentation for the plugin I’m trying to use

I have included the jQuery.min.js and jQuery UI libraries as mentioned in the above link, and as you can see in the pastebin file, but it doesn’t seem to work. Can anyone highlight what I’m missing here?

I’m pretty sure it’s a simple fix but I can’t see it because of my limited experience with jQuery. ??
Oh, if it helps, I’m also using jQuery for the Featured Image on the left side.

Thanks.