Welcome to DB.com! I'm sure you'll like it here!
IMHO, before you try supplements, try rest. Take a week or two off from training. Start with 60% weights and work your way up. Maybe even cut out cardio. See if you get past your limit that way. If you've already tried this, then maybe list what you are eating. I thought I was eating pretty clean when I first came here. Processed foods are not considered clean, even though they are better than fast food. There's always room for improvement someplace!