Load time ???

Hi All

I am having some serious issues with some of my websites loading times.
I use WPMUDEV plugins on all my sites ( i am certainly not saying they are the problem ) just kinda hoping this will show i am a loyal WPMU customer LOL. the thing is my web host have said they have had some DOS attacks and are trying to sort the problem, but this has been going on for WEEKS on some of sites. Trying to do any work is impossible as everytime i update a page the reload time is 4+ minutes. I'm not an expert so it is difficult for me to find where exactly the problem lies. sometimes when i have asked a question on here before i sometimes get a reply when someone shows me an image showing results of page errors on my site. can anyone tell me what software i could use to check to see if the issue is with my websites / plugins etc or if it is at the host end. just for reference the website is http://www.acegolftours.com
many thanks