site domain: losangeles-skincare.com I have defender

site domain:
losangeles-skincare.com

I have defender installed and support access turned on. I keep getting this error message even though the server load is minimal/non existant. the host (bluehost) said to get with wpmu dev about this. here is the error:

Your server resource usage is too close to your limit. Please try again in 15 minutes.