Website maintenance and possibly rebuilding - www.305films.com

I have the website 305films.com It was built in wordpress and was working fine in January. The GTMETRIX Score was a B, which was fine. Since then, it has become really slow, and won't even load up for GT METRIX. The main problems I am having are with the homepage slideshow, which shows video. Im not sure if this is causing the slowness, but it doesn't work properly.Either the video takes too long to load, or when it plays it skips or is low resolution. I am very happy with my design of the site, although the original designer, can't seem to fix it, and seems to blame it on the host at Go Daddy. I spoke to Go Daddy, and they said it is not a hosting issues, and I have purchased optimum speeds hosting. I wonder if it needs to be built with different plug in. I would like the slideshow to work like this competitor site: boyinthecastle.com.