Broken RSS feed shows code

I hope someone can help. A couple of days ago my rss feed began to show only code. Half of the subscribers are leaving already. I can’t find out how to fix it.

Recent changes that could be related:

I’ve been adding in & commenting out new welcome box/photo & feed subscription forms in the side bar.

Also, a java script quiz on a page, not a post. But, I commented it out to experiment & that did not seem to fix the problem.

Finally, I also updated my Facebook gadget (JS also) just to make it a little larger to show the fan number.

My site: https://rawarrior.com