How to pull Text data into my sidebar

Can somebody help me? Please see https://HART-Empire.com/code/ … I have two files …
(1) https://www.hart-empire.com/wp-content/HART-Empire_Network-RSS.html (a text file I want to modify on an ongoing basis) and
(2) https://hart-empire.com/wp-content/HART-Empire_Network-code.txt (what I want to put on website that gets updated automatically if I update (1))

I’ve been using iframes, only because I basically copied an old script I had years ago on one of my sites. Maybe it might be better in javascript or php? Right now this is screwing up templates and halting a few pages from completely loading. Any ideas?

edit:// example.. see https://1800HART.com/blog/ to see how slow it loads – it’s at the bottom of index, below cartoon