Itune apps freezing

Brand new on the forum as member, but have lurked in background for a while. I have the need for some expert advice, capable of taking a good whack over the knuckles too. I have recently had trouble with my mac, initially with the preview app on my mac. Running the latest sierra os. Basically when I attempted to view an attachment from an email in preview the app would open with the image but it seems that the app would freeze. Later I found the same thing with the App store, it would open but freeze, now Imovie is freezing, with all of these apps I have to close them with Force Quit. I am guessing that it may have been me clearing some excess back ups from time machine as the hdd was full. Not too sure about this, I seem to recall that I had trouble with preview prior. I have scanned for viruses, cleared all of the caches, reset this, reset that as suggested on some google searches. I have done a restore to latest os but has not acheived anything. I logged out and registered a new log and whilst I don't have imovie etc, I can access the itunes Apps store with this log in. Okay, ready for the rap across the knuckles...